update goctl version to 1.2.1 (#1042)

* fix symlink issue on windows for goctl

* move readlink into separate file

.codecov.yml

@@ -0,0 +1,3 @@
+comment: false
+ignore:
+  - "tools"

.github/workflows/codeql-analysis.yml

@@ -0,0 +1,67 @@
+# For most projects, this workflow file will not need changing; you simply need
+# to commit it to your repository.
+#
+# You may wish to alter this file to override the set of languages analyzed,
+# or to provide custom queries or build logic.
+#
+# ******** NOTE ********
+# We have attempted to detect the languages in your repository. Please check
+# the `language` matrix defined below to confirm you have the correct set of
+# supported CodeQL languages.
+#
+name: "CodeQL"
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    # The branches below must be a subset of the branches above
+    branches: [ master ]
+  schedule:
+    - cron: '18 19 * * 6'
+
+jobs:
+  analyze:
+    name: Analyze
+    runs-on: ubuntu-latest
+
+    strategy:
+      fail-fast: false
+      matrix:
+        language: [ 'go' ]
+        # CodeQL supports [ 'cpp', 'csharp', 'go', 'java', 'javascript', 'python' ]
+        # Learn more:
+        # https://docs.github.com/en/free-pro-team@latest/github/finding-security-vulnerabilities-and-errors-in-your-code/configuring-code-scanning#changing-the-languages-that-are-analyzed
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v2
+
+    # Initializes the CodeQL tools for scanning.
+    - name: Initialize CodeQL
+      uses: github/codeql-action/init@v1
+      with:
+        languages: ${{ matrix.language }}
+        # If you wish to specify custom queries, you can do so here or in a config file.
+        # By default, queries listed here will override any specified in a config file.
+        # Prefix the list here with "+" to use these queries and those in the config file.
+        # queries: ./path/to/local/query, your-org/your-repo/queries@main
+
+    # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
+    # If this step fails, then you should remove it and run the build manually (see below)
+    - name: Autobuild
+      uses: github/codeql-action/autobuild@v1
+
+    # ℹ️ Command-line programs to run using the OS shell.
+    # 📚 https://git.io/JvXDl
+
+    # ✏️ If the Autobuild fails above, remove it and uncomment the following three lines
+    #    and modify them (or add more) to build your code if your project
+    #    uses a compiled language
+
+    #- run: |
+    #   make bootstrap
+    #   make release
+
+    - name: Perform CodeQL Analysis
+      uses: github/codeql-action/analyze@v1

.github/workflows/go.yml

@@ -7,7 +7,6 @@ on:
     branches: [ master ]
 
 jobs:
-
   build:
     name: Build
     runs-on: ubuntu-latest
@@ -16,7 +15,7 @@ jobs:
     - name: Set up Go 1.x
       uses: actions/setup-go@v2
       with:
-        go-version: ^1.13
+        go-version: ^1.14
       id: go
 
     - name: Check out code into the Go module directory
@@ -25,10 +24,9 @@ jobs:
     - name: Get dependencies
       run: |
         go get -v -t -d ./...
-        if [ -f Gopkg.toml ]; then
-            curl https://raw.githubusercontent.com/golang/dep/master/install.sh | sh
-            dep ensure
-        fi
 
     - name: Test
-      run: go test -v -race ./...
+      run: go test -race -coverprofile=coverage.txt -covermode=atomic ./...
+
+    - name: Codecov
+      uses: codecov/codecov-action@v2

.github/workflows/issues.yml

@@ -0,0 +1,19 @@
+name: Close inactive issues
+on:
+  schedule:
+    - cron: "30 1 * * *"
+
+jobs:
+  close-issues:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/stale@v3
+        with:
+          days-before-issue-stale: 30
+          days-before-issue-close: 14
+          stale-issue-label: "stale"
+          stale-issue-message: "This issue is stale because it has been open for 30 days with no activity."
+          close-issue-message: "This issue was closed because it has been inactive for 14 days since being marked as stale."
+          days-before-pr-stale: -1
+          days-before-pr-close: -1
+          repo-token: ${{ secrets.GITHUB_TOKEN }}

.gitignore

@@ -4,15 +4,19 @@
 # Unignore all with extensions
 !*.*
 !**/Dockerfile
+!**/Makefile
 
 # Unignore all dirs
 !*/
 !api
 
+# ignore
 .idea
 **/.DS_Store
 **/logs
-!Makefile
+
+# ignore adhoc test code
+**/adhoc
 
 # gitlab ci
 .cache

.gitlab-ci.yml

@@ -1,18 +0,0 @@
-stages:
-- analysis
-
-variables:
-  GOPATH: '/runner-cache/zero'
-  GOCACHE: '/runner-cache/zero'
-  GOPROXY: 'https://goproxy.cn,direct'
-
-analysis:
-  stage: analysis
-  image: golang
-  script:
-    - go version && go env
-    - go test -short $(go list ./...) | grep -v "no test"
-  only:
-   - merge_requests
-  tags:
-    - common

.golangci.yml

@@ -1,36 +0,0 @@
-run:
-  #  concurrency: 6
-  timeout: 5m
-  skip-dirs:
-    - core
-    - doc
-    - example
-    - rest
-    - rpcx
-    - tools
-
-
-linters:
-  disable-all: true
-  enable:
-    - bodyclose
-    - deadcode
-    - errcheck
-    - gosimple
-    - govet
-    - ineffassign
-    - staticcheck
-    - structcheck
-    - typecheck
-    - unused
-    - varcheck
-#    - dupl
-
-
-linters-settings:
-
-issues:
-  exclude-rules:
-    - linters:
-        - staticcheck
-      text: 'SA1019: (baseresponse.BoolResponse|oldresponse.FormatBadRequestResponse|oldresponse.FormatResponse)|SA5008: unknown JSON option ("optional"|"default=|"range=|"options=)'

CONTRIBUTING.md

@@ -0,0 +1,102 @@
+# Contributing
+
+Welcome to go-zero!
+
+-   [Before you get started](#before-you-get-started)
+    -   [Code of Conduct](#code-of-conduct)
+    -   [Community Expectations](#community-expectations)
+-   [Getting started](#getting-started)
+-   [Your First Contribution](#your-first-contribution)
+    -   [Find something to work on](#find-something-to-work-on)
+        -   [Find a good first topic](#find-a-good-first-topic)
+        -   [Work on an Issue](#work-on-an-issue)
+        -   [File an Issue](#file-an-issue)
+-   [Contributor Workflow](#contributor-workflow)
+    -   [Creating Pull Requests](#creating-pull-requests)
+    -   [Code Review](#code-review)
+    -   [Testing](#testing)
+
+# Before you get started
+
+## Code of Conduct
+
+Please make sure to read and observe our [Code of Conduct](/code-of-conduct.md).
+
+## Community Expectations
+
+go-zero is a community project driven by its community which strives to promote a healthy, friendly and productive environment.
+go-zero is a web and rpc framework written in Go. It's born to ensure the stability of the busy sites with resilient design. Builtin goctl greatly improves the development productivity.
+
+# Getting started
+
+- Fork the repository on GitHub.
+- Make your changes on your fork repository.
+- Submit a PR.
+
+
+# Your First Contribution
+
+We will help you to contribute in different areas like filing issues, developing features, fixing critical bugs and
+getting your work reviewed and merged.
+
+If you have questions about the development process,
+feel free to [file an issue](https://github.com/tal-tech/go-zero/issues/new/choose).
+
+## Find something to work on
+
+We are always in need of help, be it fixing documentation, reporting bugs or writing some code.
+Look at places where you feel best coding practices aren't followed, code refactoring is needed or tests are missing.
+Here is how you get started.
+
+### Find a good first topic
+
+[go-zero](https://github.com/tal-tech/go-zero) has beginner-friendly issues that provide a good first issue.
+For example, [go-zero](https://github.com/tal-tech/go-zero) has
+[help wanted](https://github.com/tal-tech/go-zero/issues?q=is%3Aopen+is%3Aissue+label%3A%22help+wanted%22) and
+[good first issue](https://github.com/tal-tech/go-zero/issues?q=is%3Aopen+is%3Aissue+label%3A%22good+first+issue%22)
+labels for issues that should not need deep knowledge of the system.
+We can help new contributors who wish to work on such issues.
+
+Another good way to contribute is to find a documentation improvement, such as a missing/broken link.
+Please see [Contributing](#contributing) below for the workflow.
+
+#### Work on an issue
+
+When you are willing to take on an issue, just reply on the issue. The maintainer will assign it to you.
+
+### File an Issue
+
+While we encourage everyone to contribute code, it is also appreciated when someone reports an issue.
+
+Please follow the prompted submission guidelines while opening an issue.
+
+# Contributor Workflow
+
+Please do not ever hesitate to ask a question or send a pull request.
+
+This is a rough outline of what a contributor's workflow looks like:
+
+- Create a topic branch from where to base the contribution. This is usually master.
+- Make commits of logical units.
+- Push changes in a topic branch to a personal fork of the repository.
+- Submit a pull request to [go-zero](https://github.com/tal-tech/go-zero).
+
+## Creating Pull Requests
+
+Pull requests are often called simply "PR".
+go-zero generally follows the standard [github pull request](https://help.github.com/articles/about-pull-requests/) process.
+To submit a proposed change, please develop the code/fix and add new test cases.
+After that, run these local verifications before submitting pull request to predict the pass or
+fail of continuous integration.
+
+* Format the code with `gofmt`
+* Run the test with data race enabled `go test -race ./...`
+
+## Code Review
+
+To make it easier for your PR to receive reviews, consider the reviewers will need you to:
+
+* follow [good coding guidelines](https://github.com/golang/go/wiki/CodeReviewComments).
+* write [good commit messages](https://chris.beams.io/posts/git-commit/).
+* break large changes into a logical series of smaller patches which individually make easily understandable changes, and in aggregate solve a broader issue.
+

ROADMAP.md

@@ -0,0 +1,21 @@
+# go-zero Roadmap
+
+This document defines a high level roadmap for go-zero development and upcoming releases.
+Community and contributor involvement is vital for successfully implementing all desired items for each release.
+We hope that the items listed below will inspire further engagement from the community to keep go-zero progressing and shipping exciting and valuable features.
+
+## 2021 Q2
+- Support TLS in redis connections
+- Support service discovery through K8S watch api
+- Log full sql statements for easier sql problem solving
+
+## 2021 Q3
+- Support `goctl mock` command to start a mocking server with given `.api` file
+- Adapt builtin tracing mechanism to opentracing solutions
+- Support `goctl model pg` to support PostgreSQL code generation
+
+## 2021 Q4
+- Support `goctl doctor` command to report potential issues for given service
+- Support `context` in redis related methods for timeout and tracing
+- Support `context` in sql related methods for timeout and tracing
+- Support `context` in mongodb related methods for timeout and tracing

code-of-conduct.md

@@ -0,0 +1,76 @@
+# Contributor Covenant Code of Conduct
+
+## Our Pledge
+
+In the interest of fostering an open and welcoming environment, we as
+contributors and maintainers pledge to make participation in our project and
+our community a harassment-free experience for everyone, regardless of age, body
+size, disability, ethnicity, sex characteristics, gender identity and expression,
+level of experience, education, socio-economic status, nationality, personal
+appearance, race, religion, or sexual identity and orientation.
+
+## Our Standards
+
+Examples of behavior that contributes to creating a positive environment
+include:
+
+* Using welcoming and inclusive language
+* Being respectful of differing viewpoints and experiences
+* Gracefully accepting constructive criticism
+* Focusing on what is best for the community
+* Showing empathy towards other community members
+
+Examples of unacceptable behavior by participants include:
+
+* The use of sexualized language or imagery and unwelcome sexual attention or
+  advances
+* Trolling, insulting/derogatory comments, and personal or political attacks
+* Public or private harassment
+* Publishing others' private information, such as a physical or electronic
+  address, without explicit permission
+* Other conduct which could reasonably be considered inappropriate in a
+  professional setting
+
+## Our Responsibilities
+
+Project maintainers are responsible for clarifying the standards of acceptable
+behavior and are expected to take appropriate and fair corrective action in
+response to any instances of unacceptable behavior.
+
+Project maintainers have the right and responsibility to remove, edit, or
+reject comments, commits, code, wiki edits, issues, and other contributions
+that are not aligned to this Code of Conduct, or to ban temporarily or
+permanently any contributor for other behaviors that they deem inappropriate,
+threatening, offensive, or harmful.
+
+## Scope
+
+This Code of Conduct applies within all project spaces, and it also applies when
+an individual is representing the project or its community in public spaces.
+Examples of representing a project or community include using an official
+project e-mail address, posting via an official social media account, or acting
+as an appointed representative at an online or offline event. Representation of
+a project may be further defined and clarified by project maintainers.
+
+## Enforcement
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be
+reported by contacting the project team at [INSERT EMAIL ADDRESS]. All
+complaints will be reviewed and investigated and will result in a response that
+is deemed necessary and appropriate to the circumstances. The project team is
+obligated to maintain confidentiality with regard to the reporter of an incident.
+Further details of specific enforcement policies may be posted separately.
+
+Project maintainers who do not follow or enforce the Code of Conduct in good
+faith may face temporary or permanent repercussions as determined by other
+members of the project's leadership.
+
+## Attribution
+
+This Code of Conduct is adapted from the [Contributor Covenant][homepage], version 1.4,
+available at https://www.contributor-covenant.org/version/1/4/code-of-conduct.html
+
+[homepage]: https://www.contributor-covenant.org
+
+For answers to common questions about this code of conduct, see
+https://www.contributor-covenant.org/faq

core/bloom/bloom.go

@@ -13,15 +13,13 @@ const (
 	// maps as k in the error rate table
 	maps      = 14
 	setScript = `
-local key = KEYS[1]
 for _, offset in ipairs(ARGV) do
-	redis.call("setbit", key, offset, 1)
+	redis.call("setbit", KEYS[1], offset, 1)
 end
 `
 	testScript = `
-local key = KEYS[1]
 for _, offset in ipairs(ARGV) do
-	if tonumber(redis.call("getbit", key, offset)) == 0 then
+	if tonumber(redis.call("getbit", KEYS[1], offset)) == 0 then
 		return false
 	end
 end
@@ -29,44 +27,43 @@ return true
 `
 )
 
+// ErrTooLargeOffset indicates the offset is too large in bitset.
 var ErrTooLargeOffset = errors.New("too large offset")
 
 type (
-	BitSetProvider interface {
+	// A Filter is a bloom filter.
+	Filter struct {
+		bits   uint
+		bitSet bitSetProvider
+	}
+
+	bitSetProvider interface {
 		check([]uint) (bool, error)
 		set([]uint) error
 	}
-
-	BloomFilter struct {
-		bits   uint
-		maps   uint
-		bitSet BitSetProvider
-	}
 )
 
-// New create a BloomFilter, store is the backed redis, key is the key for the bloom filter,
+// New create a Filter, store is the backed redis, key is the key for the bloom filter,
 // bits is how many bits will be used, maps is how many hashes for each addition.
 // best practices:
 // elements - means how many actual elements
 // when maps = 14, formula: 0.7*(bits/maps), bits = 20*elements, the error rate is 0.000067 < 1e-4
 // for detailed error rate table, see http://pages.cs.wisc.edu/~cao/papers/summary-cache/node8.html
-func New(store *redis.Redis, key string, bits uint) *BloomFilter {
-	return &BloomFilter{
+func New(store *redis.Redis, key string, bits uint) *Filter {
+	return &Filter{
 		bits:   bits,
 		bitSet: newRedisBitSet(store, key, bits),
 	}
 }
 
-func (f *BloomFilter) Add(data []byte) error {
+// Add adds data into f.
+func (f *Filter) Add(data []byte) error {
 	locations := f.getLocations(data)
-	err := f.bitSet.set(locations)
-	if err != nil {
-		return err
-	}
-	return nil
+	return f.bitSet.set(locations)
 }
 
-func (f *BloomFilter) Exists(data []byte) (bool, error) {
+// Exists checks if data is in f.
+func (f *Filter) Exists(data []byte) (bool, error) {
 	locations := f.getLocations(data)
 	isSet, err := f.bitSet.check(locations)
 	if err != nil {
@@ -79,7 +76,7 @@ func (f *BloomFilter) Exists(data []byte) (bool, error) {
 	return true, nil
 }
 
-func (f *BloomFilter) getLocations(data []byte) []uint {
+func (f *Filter) getLocations(data []byte) []uint {
 	locations := make([]uint, maps)
 	for i := uint(0); i < maps; i++ {
 		hashValue := hash.Hash(append(data, byte(i)))
@@ -130,11 +127,12 @@ func (r *redisBitSet) check(offsets []uint) (bool, error) {
 		return false, err
 	}
 
-	if exists, ok := resp.(int64); !ok {
+	exists, ok := resp.(int64)
+	if !ok {
 		return false, nil
-	} else {
-		return exists == 1, nil
 	}
+
+	return exists == 1, nil
 }
 
 func (r *redisBitSet) del() error {
@@ -155,7 +153,7 @@ func (r *redisBitSet) set(offsets []uint) error {
 	_, err = r.store.Eval(setScript, []string{r.key}, args)
 	if err == redis.Nil {
 		return nil
-	} else {
-		return err
 	}
+
+	return err
 }

core/bloom/bloom_test.go

@@ -3,19 +3,15 @@ package bloom
 import (
 	"testing"
 
-	"github.com/alicebob/miniredis"
 	"github.com/stretchr/testify/assert"
-	"github.com/tal-tech/go-zero/core/stores/redis"
+	"github.com/tal-tech/go-zero/core/stores/redis/redistest"
 )
 
 func TestRedisBitSet_New_Set_Test(t *testing.T) {
-	s, err := miniredis.Run()
-	if err != nil {
-		t.Error("Miniredis could not start")
-	}
-	defer s.Close()
+	store, clean, err := redistest.CreateRedis()
+	assert.Nil(t, err)
+	defer clean()
 
-	store := redis.NewRedis(s.Addr(), redis.NodeType)
 	bitSet := newRedisBitSet(store, "test_key", 1024)
 	isSetBefore, err := bitSet.check([]uint{0})
 	if err != nil {
@@ -46,13 +42,10 @@ func TestRedisBitSet_New_Set_Test(t *testing.T) {
 }
 
 func TestRedisBitSet_Add(t *testing.T) {
-	s, err := miniredis.Run()
-	if err != nil {
-		t.Error("Miniredis could not start")
-	}
-	defer s.Close()
+	store, clean, err := redistest.CreateRedis()
+	assert.Nil(t, err)
+	defer clean()
 
-	store := redis.NewRedis(s.Addr(), redis.NodeType)
 	filter := New(store, "test_key", 64)
 	assert.Nil(t, filter.Add([]byte("hello")))
 	assert.Nil(t, filter.Add([]byte("world")))

core/breaker/breaker.go

@@ -5,17 +5,12 @@ import (
 	"fmt"
 	"strings"
 	"sync"
-	"time"
 
 	"github.com/tal-tech/go-zero/core/mathx"
 	"github.com/tal-tech/go-zero/core/proc"
 	"github.com/tal-tech/go-zero/core/stat"
 	"github.com/tal-tech/go-zero/core/stringx"
-)
-
-const (
-	StateClosed State = iota
-	StateOpen
+	"github.com/tal-tech/go-zero/core/timex"
 )
 
 const (
@@ -23,15 +18,16 @@ const (
 	timeFormat        = "15:04:05"
 )
 
-// ErrServiceUnavailable is returned when the CB state is open
+// ErrServiceUnavailable is returned when the Breaker state is open.
 var ErrServiceUnavailable = errors.New("circuit breaker is open")
 
 type (
-	State      = int32
+	// Acceptable is the func to check if the error can be accepted.
 	Acceptable func(err error) bool
 
+	// A Breaker represents a circuit breaker.
 	Breaker interface {
-		// Name returns the name of the netflixBreaker.
+		// Name returns the name of the Breaker.
 		Name() string
 
 		// Allow checks if the request is allowed.
@@ -40,37 +36,41 @@ type (
 		// If not allow, ErrServiceUnavailable will be returned.
 		Allow() (Promise, error)
 
-		// Do runs the given request if the netflixBreaker accepts it.
-		// Do returns an error instantly if the netflixBreaker rejects the request.
-		// If a panic occurs in the request, the netflixBreaker handles it as an error
+		// Do runs the given request if the Breaker accepts it.
+		// Do returns an error instantly if the Breaker rejects the request.
+		// If a panic occurs in the request, the Breaker handles it as an error
 		// and causes the same panic again.
 		Do(req func() error) error
 
-		// DoWithAcceptable runs the given request if the netflixBreaker accepts it.
-		// Do returns an error instantly if the netflixBreaker rejects the request.
-		// If a panic occurs in the request, the netflixBreaker handles it as an error
+		// DoWithAcceptable runs the given request if the Breaker accepts it.
+		// DoWithAcceptable returns an error instantly if the Breaker rejects the request.
+		// If a panic occurs in the request, the Breaker handles it as an error
 		// and causes the same panic again.
 		// acceptable checks if it's a successful call, even if the err is not nil.
 		DoWithAcceptable(req func() error, acceptable Acceptable) error
 
-		// DoWithFallback runs the given request if the netflixBreaker accepts it.
-		// DoWithFallback runs the fallback if the netflixBreaker rejects the request.
-		// If a panic occurs in the request, the netflixBreaker handles it as an error
+		// DoWithFallback runs the given request if the Breaker accepts it.
+		// DoWithFallback runs the fallback if the Breaker rejects the request.
+		// If a panic occurs in the request, the Breaker handles it as an error
 		// and causes the same panic again.
 		DoWithFallback(req func() error, fallback func(err error) error) error
 
-		// DoWithFallbackAcceptable runs the given request if the netflixBreaker accepts it.
-		// DoWithFallback runs the fallback if the netflixBreaker rejects the request.
-		// If a panic occurs in the request, the netflixBreaker handles it as an error
+		// DoWithFallbackAcceptable runs the given request if the Breaker accepts it.
+		// DoWithFallbackAcceptable runs the fallback if the Breaker rejects the request.
+		// If a panic occurs in the request, the Breaker handles it as an error
 		// and causes the same panic again.
 		// acceptable checks if it's a successful call, even if the err is not nil.
 		DoWithFallbackAcceptable(req func() error, fallback func(err error) error, acceptable Acceptable) error
 	}
 
-	BreakerOption func(breaker *circuitBreaker)
+	// Option defines the method to customize a Breaker.
+	Option func(breaker *circuitBreaker)
 
+	// Promise interface defines the callbacks that returned by Breaker.Allow.
 	Promise interface {
+		// Accept tells the Breaker that the call is successful.
 		Accept()
+		// Reject tells the Breaker that the call is failed.
 		Reject(reason string)
 	}
 
@@ -95,7 +95,9 @@ type (
 	}
 )
 
-func NewBreaker(opts ...BreakerOption) Breaker {
+// NewBreaker returns a Breaker object.
+// opts can be used to customize the Breaker.
+func NewBreaker(opts ...Option) Breaker {
 	var b circuitBreaker
 	for _, opt := range opts {
 		opt(&b)
@@ -133,7 +135,8 @@ func (cb *circuitBreaker) Name() string {
 	return cb.name
 }
 
-func WithName(name string) BreakerOption {
+// WithName returns a function to set the name of a Breaker.
+func WithName(name string) Option {
 	return func(b *circuitBreaker) {
 		b.name = name
 	}
@@ -195,23 +198,23 @@ type errorWindow struct {
 
 func (ew *errorWindow) add(reason string) {
 	ew.lock.Lock()
-	ew.reasons[ew.index] = fmt.Sprintf("%s %s", time.Now().Format(timeFormat), reason)
+	ew.reasons[ew.index] = fmt.Sprintf("%s %s", timex.Time().Format(timeFormat), reason)
 	ew.index = (ew.index + 1) % numHistoryReasons
 	ew.count = mathx.MinInt(ew.count+1, numHistoryReasons)
 	ew.lock.Unlock()
 }
 
 func (ew *errorWindow) String() string {
-	var builder strings.Builder
+	var reasons []string
 
 	ew.lock.Lock()
-	for i := ew.index + ew.count - 1; i >= ew.index; i-- {
-		builder.WriteString(ew.reasons[i%numHistoryReasons])
-		builder.WriteByte('\n')
+	// reverse order
+	for i := ew.index - 1; i >= ew.index-ew.count; i-- {
+		reasons = append(reasons, ew.reasons[(i+numHistoryReasons)%numHistoryReasons])
 	}
 	ew.lock.Unlock()
 
-	return builder.String()
+	return strings.Join(reasons, "\n")
 }
 
 type promiseWithReason struct {

core/breaker/breaker_test.go

@@ -2,7 +2,9 @@ package breaker
 
 import (
 	"errors"
+	"fmt"
 	"strconv"
+	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -33,6 +35,84 @@ func TestLogReason(t *testing.T) {
 	assert.Equal(t, numHistoryReasons, errs.count)
 }
 
+func TestErrorWindow(t *testing.T) {
+	tests := []struct {
+		name    string
+		reasons []string
+	}{
+		{
+			name: "no error",
+		},
+		{
+			name:    "one error",
+			reasons: []string{"foo"},
+		},
+		{
+			name:    "two errors",
+			reasons: []string{"foo", "bar"},
+		},
+		{
+			name:    "five errors",
+			reasons: []string{"first", "second", "third", "fourth", "fifth"},
+		},
+		{
+			name:    "six errors",
+			reasons: []string{"first", "second", "third", "fourth", "fifth", "sixth"},
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			var ew errorWindow
+			for _, reason := range test.reasons {
+				ew.add(reason)
+			}
+			var reasons []string
+			if len(test.reasons) > numHistoryReasons {
+				reasons = test.reasons[len(test.reasons)-numHistoryReasons:]
+			} else {
+				reasons = test.reasons
+			}
+			for _, reason := range reasons {
+				assert.True(t, strings.Contains(ew.String(), reason), fmt.Sprintf("actual: %s", ew.String()))
+			}
+		})
+	}
+}
+
+func TestPromiseWithReason(t *testing.T) {
+	tests := []struct {
+		name   string
+		reason string
+		expect string
+	}{
+		{
+			name: "success",
+		},
+		{
+			name:   "success",
+			reason: "fail",
+			expect: "fail",
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			promise := promiseWithReason{
+				promise: new(mockedPromise),
+				errWin:  new(errorWindow),
+			}
+			if len(test.reason) == 0 {
+				promise.Accept()
+			} else {
+				promise.Reject(test.reason)
+			}
+
+			assert.True(t, strings.Contains(promise.errWin.String(), test.expect))
+		})
+	}
+}
+
 func BenchmarkGoogleBreaker(b *testing.B) {
 	br := NewBreaker()
 	for i := 0; i < b.N; i++ {
@@ -41,3 +121,11 @@ func BenchmarkGoogleBreaker(b *testing.B) {
 		})
 	}
 }
+
+type mockedPromise struct{}
+
+func (m *mockedPromise) Accept() {
+}
+
+func (m *mockedPromise) Reject() {
+}

core/breaker/breakers.go

@@ -7,24 +7,28 @@ var (
 	breakers = make(map[string]Breaker)
 )
 
+// Do calls Breaker.Do on the Breaker with given name.
 func Do(name string, req func() error) error {
 	return do(name, func(b Breaker) error {
 		return b.Do(req)
 	})
 }
 
+// DoWithAcceptable calls Breaker.DoWithAcceptable on the Breaker with given name.
 func DoWithAcceptable(name string, req func() error, acceptable Acceptable) error {
 	return do(name, func(b Breaker) error {
 		return b.DoWithAcceptable(req, acceptable)
 	})
 }
 
+// DoWithFallback calls Breaker.DoWithFallback on the Breaker with given name.
 func DoWithFallback(name string, req func() error, fallback func(err error) error) error {
 	return do(name, func(b Breaker) error {
 		return b.DoWithFallback(req, fallback)
 	})
 }
 
+// DoWithFallbackAcceptable calls Breaker.DoWithFallbackAcceptable on the Breaker with given name.
 func DoWithFallbackAcceptable(name string, req func() error, fallback func(err error) error,
 	acceptable Acceptable) error {
 	return do(name, func(b Breaker) error {
@@ -32,6 +36,7 @@ func DoWithFallbackAcceptable(name string, req func() error, fallback func(err e
 	})
 }
 
+// GetBreaker returns the Breaker with the given name.
 func GetBreaker(name string) Breaker {
 	lock.RLock()
 	b, ok := breakers[name]
@@ -41,36 +46,23 @@ func GetBreaker(name string) Breaker {
 	}
 
 	lock.Lock()
-	defer lock.Unlock()
+	b, ok = breakers[name]
+	if !ok {
+		b = NewBreaker(WithName(name))
+		breakers[name] = b
+	}
+	lock.Unlock()
 
-	b = NewBreaker()
-	breakers[name] = b
 	return b
 }
 
-func NoBreakFor(name string) {
+// NoBreakerFor disables the circuit breaker for the given name.
+func NoBreakerFor(name string) {
 	lock.Lock()
 	breakers[name] = newNoOpBreaker()
 	lock.Unlock()
 }
 
 func do(name string, execute func(b Breaker) error) error {
-	lock.RLock()
-	b, ok := breakers[name]
-	lock.RUnlock()
-	if ok {
-		return execute(b)
-	} else {
-		lock.Lock()
-		b, ok = breakers[name]
-		if ok {
-			lock.Unlock()
-			return execute(b)
-		} else {
-			b = NewBreaker(WithName(name))
-			breakers[name] = b
-			lock.Unlock()
-			return execute(b)
-		}
-	}
+	return execute(GetBreaker(name))
 }

core/breaker/breakers_test.go

@@ -55,7 +55,7 @@ func TestBreakersDoWithAcceptable(t *testing.T) {
 }
 
 func TestBreakersNoBreakerFor(t *testing.T) {
-	NoBreakFor("any")
+	NoBreakerFor("any")
 	errDummy := errors.New("any")
 	for i := 0; i < 10000; i++ {
 		assert.Equal(t, errDummy, GetBreaker("any").Do(func() error {

core/breaker/googlebreaker.go

@@ -2,7 +2,6 @@ package breaker
 
 import (
 	"math"
-	"sync/atomic"
 	"time"
 
 	"github.com/tal-tech/go-zero/core/collection"
@@ -21,7 +20,6 @@ const (
 // see Client-Side Throttling section in https://landing.google.com/sre/sre-book/chapters/handling-overload/
 type googleBreaker struct {
 	k     float64
-	state int32
 	stat  *collection.RollingWindow
 	proba *mathx.Proba
 }
@@ -32,7 +30,6 @@ func newGoogleBreaker() *googleBreaker {
 	return &googleBreaker{
 		stat:  st,
 		k:     k,
-		state: StateClosed,
 		proba: mathx.NewProba(),
 	}
 }
@@ -43,15 +40,9 @@ func (b *googleBreaker) accept() error {
 	// https://landing.google.com/sre/sre-book/chapters/handling-overload/#eq2101
 	dropRatio := math.Max(0, (float64(total-protection)-weightedAccepts)/float64(total+1))
 	if dropRatio <= 0 {
-		if atomic.LoadInt32(&b.state) == StateOpen {
-			atomic.CompareAndSwapInt32(&b.state, StateOpen, StateClosed)
-		}
 		return nil
 	}
 
-	if atomic.LoadInt32(&b.state) == StateClosed {
-		atomic.CompareAndSwapInt32(&b.state, StateClosed, StateOpen)
-	}
 	if b.proba.TrueOnProba(dropRatio) {
 		return ErrServiceUnavailable
 	}
@@ -73,9 +64,9 @@ func (b *googleBreaker) doReq(req func() error, fallback func(err error) error,
 	if err := b.accept(); err != nil {
 		if fallback != nil {
 			return fallback(err)
-		} else {
-			return err
 		}
+
+		return err
 	}
 
 	defer func() {
@@ -103,7 +94,7 @@ func (b *googleBreaker) markFailure() {
 	b.stat.Add(0)
 }
 
-func (b *googleBreaker) history() (accepts int64, total int64) {
+func (b *googleBreaker) history() (accepts, total int64) {
 	b.stat.Reduce(func(b *collection.Bucket) {
 		accepts += int64(b.Sum)
 		total += b.Count

core/breaker/googlebreaker_test.go

@@ -2,7 +2,6 @@ package breaker
 
 import (
 	"errors"
-	"math"
 	"math/rand"
 	"testing"
 	"time"
@@ -27,7 +26,6 @@ func getGoogleBreaker() *googleBreaker {
 	return &googleBreaker{
 		stat:  st,
 		k:     5,
-		state: StateClosed,
 		proba: mathx.NewProba(),
 	}
 }
@@ -158,7 +156,7 @@ func TestGoogleBreakerSelfProtection(t *testing.T) {
 	t.Run("total request > 100, total < 2 * success", func(t *testing.T) {
 		b := getGoogleBreaker()
 		size := rand.Intn(10000)
-		accepts := int(math.Ceil(float64(size))) + 1
+		accepts := size + 1
 		markSuccess(b, accepts)
 		markFailed(b, size-accepts)
 		assert.Nil(t, b.accept())

core/cmdline/input.go

@@ -7,11 +7,13 @@ import (
 	"strings"
 )
 
+// EnterToContinue let stdin waiting for an enter key to continue.
 func EnterToContinue() {
 	fmt.Print("Press 'Enter' to continue...")
 	bufio.NewReader(os.Stdin).ReadBytes('\n')
 }
 
+// ReadLine shows prompt to stdout and read a line from stdin.
 func ReadLine(prompt string) string {
 	fmt.Print(prompt)
 	input, _ := bufio.NewReader(os.Stdin).ReadString('\n')

core/cmdline/input_test.go

@@ -0,0 +1,80 @@
+package cmdline
+
+import (
+	"fmt"
+	"os"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/tal-tech/go-zero/core/iox"
+	"github.com/tal-tech/go-zero/core/lang"
+)
+
+func TestEnterToContinue(t *testing.T) {
+	restore, err := iox.RedirectInOut()
+	assert.Nil(t, err)
+	defer restore()
+
+	var wg sync.WaitGroup
+	wg.Add(2)
+	go func() {
+		defer wg.Done()
+		fmt.Println()
+	}()
+	go func() {
+		defer wg.Done()
+		EnterToContinue()
+	}()
+
+	wait := make(chan lang.PlaceholderType)
+	go func() {
+		wg.Wait()
+		close(wait)
+	}()
+
+	select {
+	case <-time.After(time.Second):
+		t.Error("timeout")
+	case <-wait:
+	}
+}
+
+func TestReadLine(t *testing.T) {
+	r, w, err := os.Pipe()
+	assert.Nil(t, err)
+	ow := os.Stdout
+	os.Stdout = w
+	or := os.Stdin
+	os.Stdin = r
+	defer func() {
+		os.Stdin = or
+		os.Stdout = ow
+	}()
+
+	const message = "hello"
+	var wg sync.WaitGroup
+	wg.Add(2)
+	go func() {
+		defer wg.Done()
+		fmt.Println(message)
+	}()
+	go func() {
+		defer wg.Done()
+		input := ReadLine("")
+		assert.Equal(t, message, input)
+	}()
+
+	wait := make(chan lang.PlaceholderType)
+	go func() {
+		wg.Wait()
+		close(wait)
+	}()
+
+	select {
+	case <-time.After(time.Second):
+		t.Error("timeout")
+	case <-wait:
+	}
+}

core/codec/aesecb.go

@@ -10,6 +10,7 @@ import (
 	"github.com/tal-tech/go-zero/core/logx"
 )
 
+// ErrPaddingSize indicates bad padding size.
 var ErrPaddingSize = errors.New("padding size error")
 
 type ecb struct {
@@ -26,6 +27,7 @@ func newECB(b cipher.Block) *ecb {
 
 type ecbEncrypter ecb
 
+// NewECBEncrypter returns an ECB encrypter.
 func NewECBEncrypter(b cipher.Block) cipher.BlockMode {
 	return (*ecbEncrypter)(newECB(b))
 }
@@ -52,6 +54,7 @@ func (x *ecbEncrypter) CryptBlocks(dst, src []byte) {
 
 type ecbDecrypter ecb
 
+// NewECBDecrypter returns an ECB decrypter.
 func NewECBDecrypter(b cipher.Block) cipher.BlockMode {
 	return (*ecbDecrypter)(newECB(b))
 }
@@ -78,6 +81,7 @@ func (x *ecbDecrypter) CryptBlocks(dst, src []byte) {
 	}
 }
 
+// EcbDecrypt decrypts src with the given key.
 func EcbDecrypt(key, src []byte) ([]byte, error) {
 	block, err := aes.NewCipher(key)
 	if err != nil {
@@ -92,6 +96,8 @@ func EcbDecrypt(key, src []byte) ([]byte, error) {
 	return pkcs5Unpadding(decrypted, decrypter.BlockSize())
 }
 
+// EcbDecryptBase64 decrypts base64 encoded src with the given base64 encoded key.
+// The returned string is also base64 encoded.
 func EcbDecryptBase64(key, src string) (string, error) {
 	keyBytes, err := getKeyBytes(key)
 	if err != nil {
@@ -111,6 +117,7 @@ func EcbDecryptBase64(key, src string) (string, error) {
 	return base64.StdEncoding.EncodeToString(decryptedBytes), nil
 }
 
+// EcbEncrypt encrypts src with the given key.
 func EcbEncrypt(key, src []byte) ([]byte, error) {
 	block, err := aes.NewCipher(key)
 	if err != nil {
@@ -126,6 +133,8 @@ func EcbEncrypt(key, src []byte) ([]byte, error) {
 	return crypted, nil
 }
 
+// EcbEncryptBase64 encrypts base64 encoded src with the given base64 encoded key.
+// The returned string is also base64 encoded.
 func EcbEncryptBase64(key, src string) (string, error) {
 	keyBytes, err := getKeyBytes(key)
 	if err != nil {
@@ -146,15 +155,16 @@ func EcbEncryptBase64(key, src string) (string, error) {
 }
 
 func getKeyBytes(key string) ([]byte, error) {
-	if len(key) > 32 {
-		if keyBytes, err := base64.StdEncoding.DecodeString(key); err != nil {
-			return nil, err
-		} else {
-			return keyBytes, nil
-		}
+	if len(key) <= 32 {
+		return []byte(key), nil
 	}
 
-	return []byte(key), nil
+	keyBytes, err := base64.StdEncoding.DecodeString(key)
+	if err != nil {
+		return nil, err
+	}
+
+	return keyBytes, nil
 }
 
 func pkcs5Padding(ciphertext []byte, blockSize int) []byte {

core/codec/aesecb_test.go

@@ -0,0 +1,65 @@
+package codec
+
+import (
+	"encoding/base64"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestAesEcb(t *testing.T) {
+	var (
+		key     = []byte("q4t7w!z%C*F-JaNdRgUjXn2r5u8x/A?D")
+		val     = []byte("hello")
+		badKey1 = []byte("aaaaaaaaa")
+		// more than 32 chars
+		badKey2 = []byte("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
+	)
+	_, err := EcbEncrypt(badKey1, val)
+	assert.NotNil(t, err)
+	_, err = EcbEncrypt(badKey2, val)
+	assert.NotNil(t, err)
+	dst, err := EcbEncrypt(key, val)
+	assert.Nil(t, err)
+	_, err = EcbDecrypt(badKey1, dst)
+	assert.NotNil(t, err)
+	_, err = EcbDecrypt(badKey2, dst)
+	assert.NotNil(t, err)
+	_, err = EcbDecrypt(key, val)
+	// not enough block, just nil
+	assert.Nil(t, err)
+	src, err := EcbDecrypt(key, dst)
+	assert.Nil(t, err)
+	assert.Equal(t, val, src)
+}
+
+func TestAesEcbBase64(t *testing.T) {
+	const (
+		val     = "hello"
+		badKey1 = "aaaaaaaaa"
+		// more than 32 chars
+		badKey2 = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+	)
+	key := []byte("q4t7w!z%C*F-JaNdRgUjXn2r5u8x/A?D")
+	b64Key := base64.StdEncoding.EncodeToString(key)
+	b64Val := base64.StdEncoding.EncodeToString([]byte(val))
+	_, err := EcbEncryptBase64(badKey1, val)
+	assert.NotNil(t, err)
+	_, err = EcbEncryptBase64(badKey2, val)
+	assert.NotNil(t, err)
+	_, err = EcbEncryptBase64(b64Key, val)
+	assert.NotNil(t, err)
+	dst, err := EcbEncryptBase64(b64Key, b64Val)
+	assert.Nil(t, err)
+	_, err = EcbDecryptBase64(badKey1, dst)
+	assert.NotNil(t, err)
+	_, err = EcbDecryptBase64(badKey2, dst)
+	assert.NotNil(t, err)
+	_, err = EcbDecryptBase64(b64Key, val)
+	assert.NotNil(t, err)
+	src, err := EcbDecryptBase64(b64Key, dst)
+	assert.Nil(t, err)
+	b, err := base64.StdEncoding.DecodeString(src)
+	assert.Nil(t, err)
+	assert.Equal(t, val, string(b))
+}

core/codec/dh.go

@@ -11,8 +11,11 @@ import (
 // 2048-bit MODP Group
 
 var (
-	ErrInvalidPriKey    = errors.New("invalid private key")
-	ErrInvalidPubKey    = errors.New("invalid public key")
+	// ErrInvalidPriKey indicates the invalid private key.
+	ErrInvalidPriKey = errors.New("invalid private key")
+	// ErrInvalidPubKey indicates the invalid public key.
+	ErrInvalidPubKey = errors.New("invalid public key")
+	// ErrPubKeyOutOfBound indicates the public key is out of bound.
 	ErrPubKeyOutOfBound = errors.New("public key out of bound")
 
 	p, _ = new(big.Int).SetString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
@@ -20,11 +23,13 @@ var (
 	zero = big.NewInt(0)
 )
 
+// DhKey defines the Diffie Hellman key.
 type DhKey struct {
 	PriKey *big.Int
 	PubKey *big.Int
 }
 
+// ComputeKey returns a key from public key and private key.
 func ComputeKey(pubKey, priKey *big.Int) (*big.Int, error) {
 	if pubKey == nil {
 		return nil, ErrInvalidPubKey
@@ -41,6 +46,7 @@ func ComputeKey(pubKey, priKey *big.Int) (*big.Int, error) {
 	return new(big.Int).Exp(pubKey, priKey, p), nil
 }
 
+// GenerateKey returns a Diffie Hellman key.
 func GenerateKey() (*DhKey, error) {
 	var err error
 	var x *big.Int
@@ -63,10 +69,12 @@ func GenerateKey() (*DhKey, error) {
 	return key, nil
 }
 
+// NewPublicKey returns a public key from the given bytes.
 func NewPublicKey(bs []byte) *big.Int {
 	return new(big.Int).SetBytes(bs)
 }
 
+// Bytes returns public key bytes.
 func (k *DhKey) Bytes() []byte {
 	if k.PubKey == nil {
 		return nil

core/codec/dh_test.go

@@ -71,3 +71,12 @@ func TestDiffieHellmanMiddleManAttack(t *testing.T) {
 	assert.Nil(t, err)
 	assert.Equal(t, string(src), string(decryptedSrc))
 }
+
+func TestKeyBytes(t *testing.T) {
+	var empty DhKey
+	assert.Equal(t, 0, len(empty.Bytes()))
+
+	key, err := GenerateKey()
+	assert.Nil(t, err)
+	assert.True(t, len(key.Bytes()) > 0)
+}

core/codec/gzip.go

@@ -6,6 +6,9 @@ import (
 	"io"
 )
 
+const unzipLimit = 100 * 1024 * 1024 // 100MB
+
+// Gzip compresses bs.
 func Gzip(bs []byte) []byte {
 	var b bytes.Buffer
 
@@ -16,6 +19,7 @@ func Gzip(bs []byte) []byte {
 	return b.Bytes()
 }
 
+// Gunzip uncompresses bs.
 func Gunzip(bs []byte) ([]byte, error) {
 	r, err := gzip.NewReader(bytes.NewBuffer(bs))
 	if err != nil {
@@ -24,8 +28,7 @@ func Gunzip(bs []byte) ([]byte, error) {
 	defer r.Close()
 
 	var c bytes.Buffer
-	_, err = io.Copy(&c, r)
-	if err != nil {
+	if _, err = io.Copy(&c, io.LimitReader(r, unzipLimit)); err != nil {
 		return nil, err
 	}
 

core/codec/hmac.go

@@ -7,12 +7,14 @@ import (
 	"io"
 )
 
+// Hmac returns HMAC bytes for body with the given key.
 func Hmac(key []byte, body string) []byte {
 	h := hmac.New(sha256.New, key)
 	io.WriteString(h, body)
 	return h.Sum(nil)
 }
 
+// HmacBase64 returns the base64 encoded string of HMAC for body with the given key.
 func HmacBase64(key []byte, body string) string {
 	return base64.StdEncoding.EncodeToString(Hmac(key, body))
 }

core/codec/hmac_test.go

@@ -0,0 +1,19 @@
+package codec
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestHmac(t *testing.T) {
+	ret := Hmac([]byte("foo"), "bar")
+	assert.Equal(t, "f9320baf0249169e73850cd6156ded0106e2bb6ad8cab01b7bbbebe6d1065317",
+		fmt.Sprintf("%x", ret))
+}
+
+func TestHmacBase64(t *testing.T) {
+	ret := HmacBase64([]byte("foo"), "bar")
+	assert.Equal(t, "+TILrwJJFp5zhQzWFW3tAQbiu2rYyrAbe7vr5tEGUxc=", ret)
+}

core/codec/rsa.go

@@ -11,17 +11,22 @@ import (
 )
 
 var (
+	// ErrPrivateKey indicates the invalid private key.
 	ErrPrivateKey = errors.New("private key error")
-	ErrPublicKey  = errors.New("failed to parse PEM block containing the public key")
-	ErrNotRsaKey  = errors.New("key type is not RSA")
+	// ErrPublicKey indicates the invalid public key.
+	ErrPublicKey = errors.New("failed to parse PEM block containing the public key")
+	// ErrNotRsaKey indicates the invalid RSA key.
+	ErrNotRsaKey = errors.New("key type is not RSA")
 )
 
 type (
+	// RsaDecrypter represents a RSA decrypter.
 	RsaDecrypter interface {
 		Decrypt(input []byte) ([]byte, error)
 		DecryptBase64(input string) ([]byte, error)
 	}
 
+	// RsaEncrypter represents a RSA encrypter.
 	RsaEncrypter interface {
 		Encrypt(input []byte) ([]byte, error)
 	}
@@ -41,6 +46,7 @@ type (
 	}
 )
 
+// NewRsaDecrypter returns a RsaDecrypter with the given file.
 func NewRsaDecrypter(file string) (RsaDecrypter, error) {
 	content, err := ioutil.ReadFile(file)
 	if err != nil {
@@ -84,6 +90,7 @@ func (r *rsaDecrypter) DecryptBase64(input string) ([]byte, error) {
 	return r.Decrypt(base64Decoded)
 }
 
+// NewRsaEncrypter returns a RsaEncrypter with the given key.
 func NewRsaEncrypter(key []byte) (RsaEncrypter, error) {
 	block, _ := pem.Decode(key)
 	if block == nil {

core/codec/rsa_test.go

@@ -0,0 +1,58 @@
+package codec
+
+import (
+	"encoding/base64"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/tal-tech/go-zero/core/fs"
+)
+
+const (
+	priKey = `-----BEGIN RSA PRIVATE KEY-----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+-----END RSA PRIVATE KEY-----`
+	pubKey = `-----BEGIN PUBLIC KEY-----
+MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC4TJk3onpqb2RYE3wwt23J9SHL
+FstHGSkUYFLe+nl1dEKHbD+/Zt95L757J3xGTrwoTc7KCTxbrgn+stn0w52BNjj/
+kIE2ko4lbh/v8Fl14AyVR9msfKtKOnhe5FCT72mdtApr+qvzcC3q9hfXwkyQU32p
+v7q5UimZ205iKSBmgQIDAQAB
+-----END PUBLIC KEY-----`
+	testBody = `this is the content`
+)
+
+func TestCryption(t *testing.T) {
+	enc, err := NewRsaEncrypter([]byte(pubKey))
+	assert.Nil(t, err)
+	ret, err := enc.Encrypt([]byte(testBody))
+	assert.Nil(t, err)
+
+	file, err := fs.TempFilenameWithText(priKey)
+	assert.Nil(t, err)
+	dec, err := NewRsaDecrypter(file)
+	assert.Nil(t, err)
+	actual, err := dec.Decrypt(ret)
+	assert.Nil(t, err)
+	assert.Equal(t, testBody, string(actual))
+
+	actual, err = dec.DecryptBase64(base64.StdEncoding.EncodeToString(ret))
+	assert.Nil(t, err)
+	assert.Equal(t, testBody, string(actual))
+}
+
+func TestBadPubKey(t *testing.T) {
+	_, err := NewRsaEncrypter([]byte("foo"))
+	assert.Equal(t, ErrPublicKey, err)
+}

core/collection/cache.go

@@ -23,28 +23,30 @@ const (
 var emptyLruCache = emptyLru{}
 
 type (
+	// CacheOption defines the method to customize a Cache.
 	CacheOption func(cache *Cache)
 
+	// A Cache object is a in-memory cache.
 	Cache struct {
 		name           string
 		lock           sync.Mutex
 		data           map[string]interface{}
-		evicts         *list.List
 		expire         time.Duration
 		timingWheel    *TimingWheel
 		lruCache       lru
-		barrier        syncx.SharedCalls
+		barrier        syncx.SingleFlight
 		unstableExpiry mathx.Unstable
 		stats          *cacheStat
 	}
 )
 
+// NewCache returns a Cache with given expire.
 func NewCache(expire time.Duration, opts ...CacheOption) (*Cache, error) {
 	cache := &Cache{
 		data:           make(map[string]interface{}),
 		expire:         expire,
 		lruCache:       emptyLruCache,
-		barrier:        syncx.NewSharedCalls(),
+		barrier:        syncx.NewSingleFlight(),
 		unstableExpiry: mathx.NewUnstable(expiryDeviation),
 	}
 
@@ -73,6 +75,7 @@ func NewCache(expire time.Duration, opts ...CacheOption) (*Cache, error) {
 	return cache, nil
 }
 
+// Del deletes the item with the given key from c.
 func (c *Cache) Del(key string) {
 	c.lock.Lock()
 	delete(c.data, key)
@@ -81,13 +84,9 @@ func (c *Cache) Del(key string) {
 	c.timingWheel.RemoveTimer(key)
 }
 
+// Get returns the item with the given key from c.
 func (c *Cache) Get(key string) (interface{}, bool) {
-	c.lock.Lock()
-	value, ok := c.data[key]
-	if ok {
-		c.lruCache.add(key)
-	}
-	c.lock.Unlock()
+	value, ok := c.doGet(key)
 	if ok {
 		c.stats.IncrementHit()
 	} else {
@@ -97,6 +96,7 @@ func (c *Cache) Get(key string) (interface{}, bool) {
 	return value, ok
 }
 
+// Set sets value into c with key.
 func (c *Cache) Set(key string, value interface{}) {
 	c.lock.Lock()
 	_, ok := c.data[key]
@@ -112,13 +112,29 @@ func (c *Cache) Set(key string, value interface{}) {
 	}
 }
 
+// Take returns the item with the given key.
+// If the item is in c, return it directly.
+// If not, use fetch method to get the item, set into c and return it.
 func (c *Cache) Take(key string, fetch func() (interface{}, error)) (interface{}, error) {
-	val, fresh, err := c.barrier.DoEx(key, func() (interface{}, error) {
+	if val, ok := c.doGet(key); ok {
+		c.stats.IncrementHit()
+		return val, nil
+	}
+
+	var fresh bool
+	val, err := c.barrier.Do(key, func() (interface{}, error) {
+		// because O(1) on map search in memory, and fetch is an IO query
+		// so we do double check, cache might be taken by another call
+		if val, ok := c.doGet(key); ok {
+			return val, nil
+		}
+
 		v, e := fetch()
 		if e != nil {
 			return nil, e
 		}
 
+		fresh = true
 		c.Set(key, v)
 		return v, nil
 	})
@@ -129,14 +145,25 @@ func (c *Cache) Take(key string, fetch func() (interface{}, error)) (interface{}
 	if fresh {
 		c.stats.IncrementMiss()
 		return val, nil
-	} else {
-		// got the result from previous ongoing query
-		c.stats.IncrementHit()
 	}
 
+	// got the result from previous ongoing query
+	c.stats.IncrementHit()
 	return val, nil
 }
 
+func (c *Cache) doGet(key string) (interface{}, bool) {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+
+	value, ok := c.data[key]
+	if ok {
+		c.lruCache.add(key)
+	}
+
+	return value, ok
+}
+
 func (c *Cache) onEvict(key string) {
 	// already locked
 	delete(c.data, key)
@@ -149,6 +176,7 @@ func (c *Cache) size() int {
 	return len(c.data)
 }
 
+// WithLimit customizes a Cache with items up to limit.
 func WithLimit(limit int) CacheOption {
 	return func(cache *Cache) {
 		if limit > 0 {
@@ -157,6 +185,7 @@ func WithLimit(limit int) CacheOption {
 	}
 }
 
+// WithName customizes a Cache with the given name.
 func WithName(name string) CacheOption {
 	return func(cache *Cache) {
 		cache.name = name
@@ -258,18 +287,15 @@ func (cs *cacheStat) statLoop() {
 	ticker := time.NewTicker(statInterval)
 	defer ticker.Stop()
 
-	for {
-		select {
-		case <-ticker.C:
-			hit := atomic.SwapUint64(&cs.hit, 0)
-			miss := atomic.SwapUint64(&cs.miss, 0)
-			total := hit + miss
-			if total == 0 {
-				continue
-			}
-			percent := 100 * float32(hit) / float32(total)
-			logx.Statf("cache(%s) - qpm: %d, hit_ratio: %.1f%%, elements: %d, hit: %d, miss: %d",
-				cs.name, total, percent, cs.sizeCallback(), hit, miss)
+	for range ticker.C {
+		hit := atomic.SwapUint64(&cs.hit, 0)
+		miss := atomic.SwapUint64(&cs.miss, 0)
+		total := hit + miss
+		if total == 0 {
+			continue
 		}
+		percent := 100 * float32(hit) / float32(total)
+		logx.Statf("cache(%s) - qpm: %d, hit_ratio: %.1f%%, elements: %d, hit: %d, miss: %d",
+			cs.name, total, percent, cs.sizeCallback(), hit, miss)
 	}
 }

core/collection/cache_test.go

@@ -1,6 +1,7 @@
 package collection
 
 import (
+	"errors"
 	"strconv"
 	"sync"
 	"sync/atomic"
@@ -10,6 +11,8 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
+var errDummy = errors.New("dummy")
+
 func TestCacheSet(t *testing.T) {
 	cache, err := NewCache(time.Second*2, WithName("any"))
 	assert.Nil(t, err)
@@ -63,6 +66,54 @@ func TestCacheTake(t *testing.T) {
 	assert.Equal(t, int32(1), atomic.LoadInt32(&count))
 }
 
+func TestCacheTakeExists(t *testing.T) {
+	cache, err := NewCache(time.Second * 2)
+	assert.Nil(t, err)
+
+	var count int32
+	var wg sync.WaitGroup
+	for i := 0; i < 100; i++ {
+		wg.Add(1)
+		go func() {
+			cache.Set("first", "first element")
+			cache.Take("first", func() (interface{}, error) {
+				atomic.AddInt32(&count, 1)
+				time.Sleep(time.Millisecond * 100)
+				return "first element", nil
+			})
+			wg.Done()
+		}()
+	}
+	wg.Wait()
+
+	assert.Equal(t, 1, cache.size())
+	assert.Equal(t, int32(0), atomic.LoadInt32(&count))
+}
+
+func TestCacheTakeError(t *testing.T) {
+	cache, err := NewCache(time.Second * 2)
+	assert.Nil(t, err)
+
+	var count int32
+	var wg sync.WaitGroup
+	for i := 0; i < 100; i++ {
+		wg.Add(1)
+		go func() {
+			_, err := cache.Take("first", func() (interface{}, error) {
+				atomic.AddInt32(&count, 1)
+				time.Sleep(time.Millisecond * 100)
+				return "", errDummy
+			})
+			assert.Equal(t, errDummy, err)
+			wg.Done()
+		}()
+	}
+	wg.Wait()
+
+	assert.Equal(t, 0, cache.size())
+	assert.Equal(t, int32(1), atomic.LoadInt32(&count))
+}
+
 func TestCacheWithLruEvicts(t *testing.T) {
 	cache, err := NewCache(time.Minute, WithLimit(3))
 	assert.Nil(t, err)
@@ -72,9 +123,9 @@ func TestCacheWithLruEvicts(t *testing.T) {
 	cache.Set("third", "third element")
 	cache.Set("fourth", "fourth element")
 
-	value, ok := cache.Get("first")
+	_, ok := cache.Get("first")
 	assert.False(t, ok)
-	value, ok = cache.Get("second")
+	value, ok := cache.Get("second")
 	assert.True(t, ok)
 	assert.Equal(t, "second element", value)
 	value, ok = cache.Get("third")
@@ -94,9 +145,9 @@ func TestCacheWithLruEvicted(t *testing.T) {
 	cache.Set("third", "third element")
 	cache.Set("fourth", "fourth element")
 
-	value, ok := cache.Get("first")
+	_, ok := cache.Get("first")
 	assert.False(t, ok)
-	value, ok = cache.Get("second")
+	value, ok := cache.Get("second")
 	assert.True(t, ok)
 	assert.Equal(t, "second element", value)
 	cache.Set("fifth", "fifth element")

core/collection/fifo.go

@@ -2,6 +2,7 @@ package collection
 
 import "sync"
 
+// A Queue is a FIFO queue.
 type Queue struct {
 	lock     sync.Mutex
 	elements []interface{}
@@ -11,6 +12,7 @@ type Queue struct {
 	count    int
 }
 
+// NewQueue returns a Queue object.
 func NewQueue(size int) *Queue {
 	return &Queue{
 		elements: make([]interface{}, size),
@@ -18,6 +20,7 @@ func NewQueue(size int) *Queue {
 	}
 }
 
+// Empty checks if q is empty.
 func (q *Queue) Empty() bool {
 	q.lock.Lock()
 	empty := q.count == 0
@@ -26,6 +29,7 @@ func (q *Queue) Empty() bool {
 	return empty
 }
 
+// Put puts element into q at the last position.
 func (q *Queue) Put(element interface{}) {
 	q.lock.Lock()
 	defer q.lock.Unlock()
@@ -44,6 +48,7 @@ func (q *Queue) Put(element interface{}) {
 	q.count++
 }
 
+// Take takes the first element out of q if not empty.
 func (q *Queue) Take() (interface{}, bool) {
 	q.lock.Lock()
 	defer q.lock.Unlock()

core/collection/ring.go

@@ -1,22 +1,39 @@
 package collection
 
+import "sync"
+
+// A Ring can be used as fixed size ring.
 type Ring struct {
 	elements []interface{}
 	index    int
+	lock     sync.Mutex
 }
 
+// NewRing returns a Ring object with the given size n.
 func NewRing(n int) *Ring {
+	if n < 1 {
+		panic("n should be greater than 0")
+	}
+
 	return &Ring{
 		elements: make([]interface{}, n),
 	}
 }
 
+// Add adds v into r.
 func (r *Ring) Add(v interface{}) {
+	r.lock.Lock()
+	defer r.lock.Unlock()
+
 	r.elements[r.index%len(r.elements)] = v
 	r.index++
 }
 
+// Take takes all items from r.
 func (r *Ring) Take() []interface{} {
+	r.lock.Lock()
+	defer r.lock.Unlock()
+
 	var size int
 	var start int
 	if r.index > len(r.elements) {

core/collection/ring_test.go

@@ -1,11 +1,18 @@
 package collection
 
 import (
+	"sync"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
 )
 
+func TestNewRing(t *testing.T) {
+	assert.Panics(t, func() {
+		NewRing(0)
+	})
+}
+
 func TestRingLess(t *testing.T) {
 	ring := NewRing(5)
 	for i := 0; i < 3; i++ {
@@ -23,3 +30,30 @@ func TestRingMore(t *testing.T) {
 	elements := ring.Take()
 	assert.ElementsMatch(t, []interface{}{6, 7, 8, 9, 10}, elements)
 }
+
+func TestRingAdd(t *testing.T) {
+	ring := NewRing(5051)
+	wg := sync.WaitGroup{}
+	for i := 1; i <= 100; i++ {
+		wg.Add(1)
+		go func(i int) {
+			defer wg.Done()
+			for j := 1; j <= i; j++ {
+				ring.Add(i)
+			}
+		}(i)
+	}
+	wg.Wait()
+	assert.Equal(t, 5050, len(ring.Take()))
+}
+
+func BenchmarkRingAdd(b *testing.B) {
+	ring := NewRing(500)
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			for i := 0; i < b.N; i++ {
+				ring.Add(i)
+			}
+		}
+	})
+}

core/collection/rollingwindow.go

@@ -8,8 +8,10 @@ import (
 )
 
 type (
+	// RollingWindowOption let callers customize the RollingWindow.
 	RollingWindowOption func(rollingWindow *RollingWindow)
 
+	// RollingWindow defines a rolling window to calculate the events in buckets with time interval.
 	RollingWindow struct {
 		lock          sync.RWMutex
 		size          int
@@ -17,11 +19,17 @@ type (
 		interval      time.Duration
 		offset        int
 		ignoreCurrent bool
-		lastTime      time.Duration
+		lastTime      time.Duration // start time of the last bucket
 	}
 )
 
+// NewRollingWindow returns a RollingWindow that with size buckets and time interval,
+// use opts to customize the RollingWindow.
 func NewRollingWindow(size int, interval time.Duration, opts ...RollingWindowOption) *RollingWindow {
+	if size < 1 {
+		panic("size must be greater than 0")
+	}
+
 	w := &RollingWindow{
 		size:     size,
 		win:      newWindow(size),
@@ -34,6 +42,7 @@ func NewRollingWindow(size int, interval time.Duration, opts ...RollingWindowOpt
 	return w
 }
 
+// Add adds value to current bucket.
 func (rw *RollingWindow) Add(v float64) {
 	rw.lock.Lock()
 	defer rw.lock.Unlock()
@@ -41,6 +50,7 @@ func (rw *RollingWindow) Add(v float64) {
 	rw.win.add(rw.offset, v)
 }
 
+// Reduce runs fn on all buckets, ignore current bucket if ignoreCurrent was set.
 func (rw *RollingWindow) Reduce(fn func(b *Bucket)) {
 	rw.lock.RLock()
 	defer rw.lock.RUnlock()
@@ -63,36 +73,30 @@ func (rw *RollingWindow) span() int {
 	offset := int(timex.Since(rw.lastTime) / rw.interval)
 	if 0 <= offset && offset < rw.size {
 		return offset
-	} else {
-		return rw.size
 	}
+
+	return rw.size
 }
 
 func (rw *RollingWindow) updateOffset() {
 	span := rw.span()
-	if span > 0 {
-		offset := rw.offset
-		// reset expired buckets
-		start := offset + 1
-		steps := start + span
-		var remainder int
-		if steps > rw.size {
-			remainder = steps - rw.size
-			steps = rw.size
-		}
-		for i := start; i < steps; i++ {
-			rw.win.resetBucket(i)
-			offset = i
-		}
-		for i := 0; i < remainder; i++ {
-			rw.win.resetBucket(i)
-			offset = i
-		}
-		rw.offset = offset
-		rw.lastTime = timex.Now()
+	if span <= 0 {
+		return
 	}
+
+	offset := rw.offset
+	// reset expired buckets
+	for i := 0; i < span; i++ {
+		rw.win.resetBucket((offset + i + 1) % rw.size)
+	}
+
+	rw.offset = (offset + span) % rw.size
+	now := timex.Now()
+	// align to interval time boundary
+	rw.lastTime = now - (now-rw.lastTime)%rw.interval
 }
 
+// Bucket defines the bucket that holds sum and num of additions.
 type Bucket struct {
 	Sum   float64
 	Count int64
@@ -114,9 +118,9 @@ type window struct {
 }
 
 func newWindow(size int) *window {
-	var buckets []*Bucket
+	buckets := make([]*Bucket, size)
 	for i := 0; i < size; i++ {
-		buckets = append(buckets, new(Bucket))
+		buckets[i] = new(Bucket)
 	}
 	return &window{
 		buckets: buckets,
@@ -130,14 +134,15 @@ func (w *window) add(offset int, v float64) {
 
 func (w *window) reduce(start, count int, fn func(b *Bucket)) {
 	for i := 0; i < count; i++ {
-		fn(w.buckets[(start+i)%len(w.buckets)])
+		fn(w.buckets[(start+i)%w.size])
 	}
 }
 
 func (w *window) resetBucket(offset int) {
-	w.buckets[offset].reset()
+	w.buckets[offset%w.size].reset()
 }
 
+// IgnoreCurrentBucket lets the Reduce call ignore current bucket.
 func IgnoreCurrentBucket() RollingWindowOption {
 	return func(w *RollingWindow) {
 		w.ignoreCurrent = true

core/collection/rollingwindow_test.go

@@ -11,6 +11,13 @@ import (
 
 const duration = time.Millisecond * 50
 
+func TestNewRollingWindow(t *testing.T) {
+	assert.NotNil(t, NewRollingWindow(10, time.Second))
+	assert.Panics(t, func() {
+		NewRollingWindow(0, time.Second)
+	})
+}
+
 func TestRollingWindowAdd(t *testing.T) {
 	const size = 3
 	r := NewRollingWindow(size, duration)
@@ -81,7 +88,7 @@ func TestRollingWindowReduce(t *testing.T) {
 	for _, test := range tests {
 		t.Run(stringx.Rand(), func(t *testing.T) {
 			r := test.win
-			for x := 0; x < size; x = x + 1 {
+			for x := 0; x < size; x++ {
 				for i := 0; i <= x; i++ {
 					r.Add(float64(i))
 				}
@@ -98,10 +105,41 @@ func TestRollingWindowReduce(t *testing.T) {
 	}
 }
 
+func TestRollingWindowBucketTimeBoundary(t *testing.T) {
+	const size = 3
+	interval := time.Millisecond * 30
+	r := NewRollingWindow(size, interval)
+	listBuckets := func() []float64 {
+		var buckets []float64
+		r.Reduce(func(b *Bucket) {
+			buckets = append(buckets, b.Sum)
+		})
+		return buckets
+	}
+	assert.Equal(t, []float64{0, 0, 0}, listBuckets())
+	r.Add(1)
+	assert.Equal(t, []float64{0, 0, 1}, listBuckets())
+	time.Sleep(time.Millisecond * 45)
+	r.Add(2)
+	r.Add(3)
+	assert.Equal(t, []float64{0, 1, 5}, listBuckets())
+	// sleep time should be less than interval, and make the bucket change happen
+	time.Sleep(time.Millisecond * 20)
+	r.Add(4)
+	r.Add(5)
+	r.Add(6)
+	assert.Equal(t, []float64{1, 5, 15}, listBuckets())
+	time.Sleep(time.Millisecond * 100)
+	r.Add(7)
+	r.Add(8)
+	r.Add(9)
+	assert.Equal(t, []float64{0, 0, 24}, listBuckets())
+}
+
 func TestRollingWindowDataRace(t *testing.T) {
 	const size = 3
 	r := NewRollingWindow(size, duration)
-	var stop = make(chan bool)
+	stop := make(chan bool)
 	go func() {
 		for {
 			select {

core/collection/safemap.go

@@ -18,6 +18,7 @@ type SafeMap struct {
 	dirtyNew    map[interface{}]interface{}
 }
 
+// NewSafeMap returns a SafeMap.
 func NewSafeMap() *SafeMap {
 	return &SafeMap{
 		dirtyOld: make(map[interface{}]interface{}),
@@ -25,6 +26,7 @@ func NewSafeMap() *SafeMap {
 	}
 }
 
+// Del deletes the value with the given key from m.
 func (m *SafeMap) Del(key interface{}) {
 	m.lock.Lock()
 	if _, ok := m.dirtyOld[key]; ok {
@@ -53,18 +55,20 @@ func (m *SafeMap) Del(key interface{}) {
 	m.lock.Unlock()
 }
 
+// Get gets the value with the given key from m.
 func (m *SafeMap) Get(key interface{}) (interface{}, bool) {
 	m.lock.RLock()
 	defer m.lock.RUnlock()
 
 	if val, ok := m.dirtyOld[key]; ok {
 		return val, true
-	} else {
-		val, ok := m.dirtyNew[key]
-		return val, ok
 	}
+
+	val, ok := m.dirtyNew[key]
+	return val, ok
 }
 
+// Set sets the value into m with the given key.
 func (m *SafeMap) Set(key, value interface{}) {
 	m.lock.Lock()
 	if m.deletionOld <= maxDeletion {
@@ -83,6 +87,7 @@ func (m *SafeMap) Set(key, value interface{}) {
 	m.lock.Unlock()
 }
 
+// Size returns the size of m.
 func (m *SafeMap) Size() int {
 	m.lock.RLock()
 	size := len(m.dirtyOld) + len(m.dirtyNew)

core/collection/set.go

@@ -15,11 +15,13 @@ const (
 	stringType
 )
 
+// Set is not thread-safe, for concurrent use, make sure to use it with synchronization.
 type Set struct {
 	data map[interface{}]lang.PlaceholderType
 	tp   int
 }
 
+// NewSet returns a managed Set, can only put the values with the same type.
 func NewSet() *Set {
 	return &Set{
 		data: make(map[interface{}]lang.PlaceholderType),
@@ -27,6 +29,7 @@ func NewSet() *Set {
 	}
 }
 
+// NewUnmanagedSet returns a unmanaged Set, which can put values with different types.
 func NewUnmanagedSet() *Set {
 	return &Set{
 		data: make(map[interface{}]lang.PlaceholderType),
@@ -34,42 +37,49 @@ func NewUnmanagedSet() *Set {
 	}
 }
 
+// Add adds i into s.
 func (s *Set) Add(i ...interface{}) {
 	for _, each := range i {
 		s.add(each)
 	}
 }
 
+// AddInt adds int values ii into s.
 func (s *Set) AddInt(ii ...int) {
 	for _, each := range ii {
 		s.add(each)
 	}
 }
 
+// AddInt64 adds int64 values ii into s.
 func (s *Set) AddInt64(ii ...int64) {
 	for _, each := range ii {
 		s.add(each)
 	}
 }
 
+// AddUint adds uint values ii into s.
 func (s *Set) AddUint(ii ...uint) {
 	for _, each := range ii {
 		s.add(each)
 	}
 }
 
+// AddUint64 adds uint64 values ii into s.
 func (s *Set) AddUint64(ii ...uint64) {
 	for _, each := range ii {
 		s.add(each)
 	}
 }
 
+// AddStr adds string values ss into s.
 func (s *Set) AddStr(ss ...string) {
 	for _, each := range ss {
 		s.add(each)
 	}
 }
 
+// Contains checks if i is in s.
 func (s *Set) Contains(i interface{}) bool {
 	if len(s.data) == 0 {
 		return false
@@ -80,6 +90,7 @@ func (s *Set) Contains(i interface{}) bool {
 	return ok
 }
 
+// Keys returns the keys in s.
 func (s *Set) Keys() []interface{} {
 	var keys []interface{}
 
@@ -90,13 +101,12 @@ func (s *Set) Keys() []interface{} {
 	return keys
 }
 
+// KeysInt returns the int keys in s.
 func (s *Set) KeysInt() []int {
 	var keys []int
 
 	for key := range s.data {
-		if intKey, ok := key.(int); !ok {
-			continue
-		} else {
+		if intKey, ok := key.(int); ok {
 			keys = append(keys, intKey)
 		}
 	}
@@ -104,13 +114,12 @@ func (s *Set) KeysInt() []int {
 	return keys
 }
 
+// KeysInt64 returns int64 keys in s.
 func (s *Set) KeysInt64() []int64 {
 	var keys []int64
 
 	for key := range s.data {
-		if intKey, ok := key.(int64); !ok {
-			continue
-		} else {
+		if intKey, ok := key.(int64); ok {
 			keys = append(keys, intKey)
 		}
 	}
@@ -118,13 +127,12 @@ func (s *Set) KeysInt64() []int64 {
 	return keys
 }
 
+// KeysUint returns uint keys in s.
 func (s *Set) KeysUint() []uint {
 	var keys []uint
 
 	for key := range s.data {
-		if intKey, ok := key.(uint); !ok {
-			continue
-		} else {
+		if intKey, ok := key.(uint); ok {
 			keys = append(keys, intKey)
 		}
 	}
@@ -132,13 +140,12 @@ func (s *Set) KeysUint() []uint {
 	return keys
 }
 
+// KeysUint64 returns uint64 keys in s.
 func (s *Set) KeysUint64() []uint64 {
 	var keys []uint64
 
 	for key := range s.data {
-		if intKey, ok := key.(uint64); !ok {
-			continue
-		} else {
+		if intKey, ok := key.(uint64); ok {
 			keys = append(keys, intKey)
 		}
 	}
@@ -146,13 +153,12 @@ func (s *Set) KeysUint64() []uint64 {
 	return keys
 }
 
+// KeysStr returns string keys in s.
 func (s *Set) KeysStr() []string {
 	var keys []string
 
 	for key := range s.data {
-		if strKey, ok := key.(string); !ok {
-			continue
-		} else {
+		if strKey, ok := key.(string); ok {
 			keys = append(keys, strKey)
 		}
 	}
@@ -160,11 +166,13 @@ func (s *Set) KeysStr() []string {
 	return keys
 }
 
+// Remove removes i from s.
 func (s *Set) Remove(i interface{}) {
 	s.validate(i)
 	delete(s.data, i)
 }
 
+// Count returns the number of items in s.
 func (s *Set) Count() int {
 	return len(s.data)
 }
@@ -182,10 +190,7 @@ func (s *Set) add(i interface{}) {
 }
 
 func (s *Set) setType(i interface{}) {
-	if s.tp != untyped {
-		return
-	}
-
+	// s.tp can only be untyped here
 	switch i.(type) {
 	case int:
 		s.tp = intType

core/collection/set_test.go

@@ -5,8 +5,13 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/tal-tech/go-zero/core/logx"
 )
 
+func init() {
+	logx.Disable()
+}
+
 func BenchmarkRawSet(b *testing.B) {
 	m := make(map[interface{}]struct{})
 	for i := 0; i < b.N; i++ {
@@ -147,3 +152,51 @@ func TestCount(t *testing.T) {
 	// then
 	assert.Equal(t, set.Count(), 3)
 }
+
+func TestKeysIntMismatch(t *testing.T) {
+	set := NewSet()
+	set.add(int64(1))
+	set.add(2)
+	vals := set.KeysInt()
+	assert.EqualValues(t, []int{2}, vals)
+}
+
+func TestKeysInt64Mismatch(t *testing.T) {
+	set := NewSet()
+	set.add(1)
+	set.add(int64(2))
+	vals := set.KeysInt64()
+	assert.EqualValues(t, []int64{2}, vals)
+}
+
+func TestKeysUintMismatch(t *testing.T) {
+	set := NewSet()
+	set.add(1)
+	set.add(uint(2))
+	vals := set.KeysUint()
+	assert.EqualValues(t, []uint{2}, vals)
+}
+
+func TestKeysUint64Mismatch(t *testing.T) {
+	set := NewSet()
+	set.add(1)
+	set.add(uint64(2))
+	vals := set.KeysUint64()
+	assert.EqualValues(t, []uint64{2}, vals)
+}
+
+func TestKeysStrMismatch(t *testing.T) {
+	set := NewSet()
+	set.add(1)
+	set.add("2")
+	vals := set.KeysStr()
+	assert.EqualValues(t, []string{"2"}, vals)
+}
+
+func TestSetType(t *testing.T) {
+	set := NewUnmanagedSet()
+	set.add(1)
+	set.add("2")
+	vals := set.Keys()
+	assert.ElementsMatch(t, []interface{}{1, "2"}, vals)
+}

core/collection/timingwheel.go

@@ -13,8 +13,10 @@ import (
 const drainWorkers = 8
 
 type (
+	// Execute defines the method to execute the task.
 	Execute func(key, value interface{})
 
+	// A TimingWheel is a timing wheel object to schedule tasks.
 	TimingWheel struct {
 		interval      time.Duration
 		ticker        timex.Ticker
@@ -54,6 +56,7 @@ type (
 	}
 )
 
+// NewTimingWheel returns a TimingWheel.
 func NewTimingWheel(interval time.Duration, numSlots int, execute Execute) (*TimingWheel, error) {
 	if interval <= 0 || numSlots <= 0 || execute == nil {
 		return nil, fmt.Errorf("interval: %v, slots: %d, execute: %p", interval, numSlots, execute)
@@ -85,10 +88,12 @@ func newTimingWheelWithClock(interval time.Duration, numSlots int, execute Execu
 	return tw, nil
 }
 
+// Drain drains all items and executes them.
 func (tw *TimingWheel) Drain(fn func(key, value interface{})) {
 	tw.drainChannel <- fn
 }
 
+// MoveTimer moves the task with the given key to the given delay.
 func (tw *TimingWheel) MoveTimer(key interface{}, delay time.Duration) {
 	if delay <= 0 || key == nil {
 		return
@@ -100,6 +105,7 @@ func (tw *TimingWheel) MoveTimer(key interface{}, delay time.Duration) {
 	}
 }
 
+// RemoveTimer removes the task with the given key.
 func (tw *TimingWheel) RemoveTimer(key interface{}) {
 	if key == nil {
 		return
@@ -108,6 +114,7 @@ func (tw *TimingWheel) RemoveTimer(key interface{}) {
 	tw.removeChannel <- key
 }
 
+// SetTimer sets the task value with the given key to the delay.
 func (tw *TimingWheel) SetTimer(key, value interface{}, delay time.Duration) {
 	if delay <= 0 || key == nil {
 		return
@@ -122,6 +129,7 @@ func (tw *TimingWheel) SetTimer(key, value interface{}, delay time.Duration) {
 	}
 }
 
+// Stop stops tw.
 func (tw *TimingWheel) Stop() {
 	close(tw.stopChannel)
 }
@@ -143,7 +151,7 @@ func (tw *TimingWheel) drainAll(fn func(key, value interface{})) {
 	}
 }
 
-func (tw *TimingWheel) getPositionAndCircle(d time.Duration) (pos int, circle int) {
+func (tw *TimingWheel) getPositionAndCircle(d time.Duration) (pos, circle int) {
 	steps := int(d / tw.interval)
 	pos = (tw.tickedPos + steps) % tw.numSlots
 	circle = (steps - 1) / tw.numSlots
@@ -204,6 +212,7 @@ func (tw *TimingWheel) removeTask(key interface{}) {
 
 	timer := val.(*positionEntry)
 	timer.item.removed = true
+	tw.timers.Del(key)
 }
 
 func (tw *TimingWheel) run() {
@@ -248,7 +257,6 @@ func (tw *TimingWheel) scanAndRunTasks(l *list.List) {
 		if task.removed {
 			next := e.Next()
 			l.Remove(e)
-			tw.timers.Del(task.key)
 			e = next
 			continue
 		} else if task.circle > 0 {
@@ -301,6 +309,7 @@ func (tw *TimingWheel) setTask(task *timingEntry) {
 func (tw *TimingWheel) setTimerPosition(pos int, task *timingEntry) {
 	if val, ok := tw.timers.Get(task.key); ok {
 		timer := val.(*positionEntry)
+		timer.item = task
 		timer.pos = pos
 	} else {
 		tw.timers.Set(task.key, &positionEntry{

core/collection/timingwheel_test.go

@@ -213,7 +213,10 @@ func TestTimingWheel_SetTimer(t *testing.T) {
 	}
 
 	for _, test := range tests {
+		test := test
 		t.Run(stringx.RandId(), func(t *testing.T) {
+			t.Parallel()
+
 			var count int32
 			ticker := timex.NewFakeTicker()
 			tick := func() {
@@ -291,7 +294,10 @@ func TestTimingWheel_SetAndMoveThenStart(t *testing.T) {
 	}
 
 	for _, test := range tests {
+		test := test
 		t.Run(stringx.RandId(), func(t *testing.T) {
+			t.Parallel()
+
 			var count int32
 			ticker := timex.NewFakeTicker()
 			tick := func() {
@@ -376,7 +382,10 @@ func TestTimingWheel_SetAndMoveTwice(t *testing.T) {
 	}
 
 	for _, test := range tests {
+		test := test
 		t.Run(stringx.RandId(), func(t *testing.T) {
+			t.Parallel()
+
 			var count int32
 			ticker := timex.NewFakeTicker()
 			tick := func() {
@@ -454,7 +463,10 @@ func TestTimingWheel_ElapsedAndSet(t *testing.T) {
 	}
 
 	for _, test := range tests {
+		test := test
 		t.Run(stringx.RandId(), func(t *testing.T) {
+			t.Parallel()
+
 			var count int32
 			ticker := timex.NewFakeTicker()
 			tick := func() {
@@ -542,7 +554,10 @@ func TestTimingWheel_ElapsedAndSetThenMove(t *testing.T) {
 	}
 
 	for _, test := range tests {
+		test := test
 		t.Run(stringx.RandId(), func(t *testing.T) {
+			t.Parallel()
+
 			var count int32
 			ticker := timex.NewFakeTicker()
 			tick := func() {
@@ -579,6 +594,31 @@ func TestTimingWheel_ElapsedAndSetThenMove(t *testing.T) {
 	}
 }
 
+func TestMoveAndRemoveTask(t *testing.T) {
+	ticker := timex.NewFakeTicker()
+	tick := func(v int) {
+		for i := 0; i < v; i++ {
+			ticker.Tick()
+		}
+	}
+	var keys []int
+	tw, _ := newTimingWheelWithClock(testStep, 10, func(k, v interface{}) {
+		assert.Equal(t, "any", k)
+		assert.Equal(t, 3, v.(int))
+		keys = append(keys, v.(int))
+		ticker.Done()
+	}, ticker)
+	defer tw.Stop()
+	tw.SetTimer("any", 3, testStep*8)
+	tick(6)
+	tw.MoveTimer("any", testStep*7)
+	tick(3)
+	tw.RemoveTimer("any")
+	tick(30)
+	time.Sleep(time.Millisecond)
+	assert.Equal(t, 0, len(keys))
+}
+
 func BenchmarkTimingWheel(b *testing.B) {
 	b.ReportAllocs()
 

core/conf/config.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"io/ioutil"
 	"log"
+	"os"
 	"path"
 
 	"github.com/tal-tech/go-zero/core/mapping"
@@ -15,26 +16,43 @@ var loaders = map[string]func([]byte, interface{}) error{
 	".yml":  LoadConfigFromYamlBytes,
 }
 
-func LoadConfig(file string, v interface{}) error {
-	if content, err := ioutil.ReadFile(file); err != nil {
+// LoadConfig loads config into v from file, .json, .yaml and .yml are acceptable.
+func LoadConfig(file string, v interface{}, opts ...Option) error {
+	content, err := ioutil.ReadFile(file)
+	if err != nil {
 		return err
-	} else if loader, ok := loaders[path.Ext(file)]; ok {
-		return loader(content, v)
-	} else {
-		return fmt.Errorf("unrecoginized file type: %s", file)
 	}
+
+	loader, ok := loaders[path.Ext(file)]
+	if !ok {
+		return fmt.Errorf("unrecognized file type: %s", file)
+	}
+
+	var opt options
+	for _, o := range opts {
+		o(&opt)
+	}
+
+	if opt.env {
+		return loader([]byte(os.ExpandEnv(string(content))), v)
+	}
+
+	return loader(content, v)
 }
 
+// LoadConfigFromJsonBytes loads config into v from content json bytes.
 func LoadConfigFromJsonBytes(content []byte, v interface{}) error {
 	return mapping.UnmarshalJsonBytes(content, v)
 }
 
+// LoadConfigFromYamlBytes loads config into v from content yaml bytes.
 func LoadConfigFromYamlBytes(content []byte, v interface{}) error {
 	return mapping.UnmarshalYamlBytes(content, v)
 }
 
-func MustLoad(path string, v interface{}) {
-	if err := LoadConfig(path, v); err != nil {
+// MustLoad loads config into v from path, exits on error.
+func MustLoad(path string, v interface{}, opts ...Option) {
+	if err := LoadConfig(path, v, opts...); err != nil {
 		log.Fatalf("error: config file %s, %s", path, err.Error())
 	}
 }

core/conf/config_test.go

@@ -0,0 +1,112 @@
+package conf
+
+import (
+	"io/ioutil"
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/tal-tech/go-zero/core/fs"
+	"github.com/tal-tech/go-zero/core/hash"
+)
+
+func TestLoadConfig_notExists(t *testing.T) {
+	assert.NotNil(t, LoadConfig("not_a_file", nil))
+}
+
+func TestLoadConfig_notRecogFile(t *testing.T) {
+	filename, err := fs.TempFilenameWithText("hello")
+	assert.Nil(t, err)
+	defer os.Remove(filename)
+	assert.NotNil(t, LoadConfig(filename, nil))
+}
+
+func TestConfigJson(t *testing.T) {
+	tests := []string{
+		".json",
+		".yaml",
+		".yml",
+	}
+	text := `{
+	"a": "foo",
+	"b": 1,
+	"c": "${FOO}",
+	"d": "abcd!@#$112"
+}`
+	for _, test := range tests {
+		test := test
+		t.Run(test, func(t *testing.T) {
+			os.Setenv("FOO", "2")
+			defer os.Unsetenv("FOO")
+			tmpfile, err := createTempFile(test, text)
+			assert.Nil(t, err)
+			defer os.Remove(tmpfile)
+
+			var val struct {
+				A string `json:"a"`
+				B int    `json:"b"`
+				C string `json:"c"`
+				D string `json:"d"`
+			}
+			MustLoad(tmpfile, &val)
+			assert.Equal(t, "foo", val.A)
+			assert.Equal(t, 1, val.B)
+			assert.Equal(t, "${FOO}", val.C)
+			assert.Equal(t, "abcd!@#$112", val.D)
+		})
+	}
+}
+
+func TestConfigJsonEnv(t *testing.T) {
+	tests := []string{
+		".json",
+		".yaml",
+		".yml",
+	}
+	text := `{
+	"a": "foo",
+	"b": 1,
+	"c": "${FOO}",
+	"d": "abcd!@#$a12 3"
+}`
+	for _, test := range tests {
+		test := test
+		t.Run(test, func(t *testing.T) {
+			os.Setenv("FOO", "2")
+			defer os.Unsetenv("FOO")
+			tmpfile, err := createTempFile(test, text)
+			assert.Nil(t, err)
+			defer os.Remove(tmpfile)
+
+			var val struct {
+				A string `json:"a"`
+				B int    `json:"b"`
+				C string `json:"c"`
+				D string `json:"d"`
+			}
+			MustLoad(tmpfile, &val, UseEnv())
+			assert.Equal(t, "foo", val.A)
+			assert.Equal(t, 1, val.B)
+			assert.Equal(t, "2", val.C)
+			assert.Equal(t, "abcd!@# 3", val.D)
+		})
+	}
+}
+
+func createTempFile(ext, text string) (string, error) {
+	tmpfile, err := ioutil.TempFile(os.TempDir(), hash.Md5Hex([]byte(text))+"*"+ext)
+	if err != nil {
+		return "", err
+	}
+
+	if err := ioutil.WriteFile(tmpfile.Name(), []byte(text), os.ModeTemporary); err != nil {
+		return "", err
+	}
+
+	filename := tmpfile.Name()
+	if err = tmpfile.Close(); err != nil {
+		return "", err
+	}
+
+	return filename, nil
+}

core/conf/options.go

@@ -0,0 +1,17 @@
+package conf
+
+type (
+	// Option defines the method to customize the config options.
+	Option func(opt *options)
+
+	options struct {
+		env bool
+	}
+)
+
+// UseEnv customizes the config to use environment variables.
+func UseEnv() Option {
+	return func(opt *options) {
+		opt.env = true
+	}
+}

core/conf/properties.go

@@ -2,6 +2,7 @@ package conf
 
 import (
 	"fmt"
+	"os"
 	"strconv"
 	"strings"
 	"sync"
@@ -30,12 +31,17 @@ type mapBasedProperties struct {
 	lock       sync.RWMutex
 }
 
-// Loads the properties into a properties configuration instance. May return the
-// configuration itself along with an error that indicates if there was a problem loading the configuration.
-func LoadProperties(filename string) (Properties, error) {
+// LoadProperties loads the properties into a properties configuration instance.
+// Returns an error that indicates if there was a problem loading the configuration.
+func LoadProperties(filename string, opts ...Option) (Properties, error) {
 	lines, err := iox.ReadTextLines(filename, iox.WithoutBlank(), iox.OmitWithPrefix("#"))
 	if err != nil {
-		return nil, nil
+		return nil, err
+	}
+
+	var opt options
+	for _, o := range opts {
+		o(&opt)
 	}
 
 	raw := make(map[string]string)
@@ -50,7 +56,11 @@ func LoadProperties(filename string) (Properties, error) {
 
 		key := strings.TrimSpace(pair[0])
 		value := strings.TrimSpace(pair[1])
-		raw[key] = value
+		if opt.env {
+			raw[key] = os.ExpandEnv(value)
+		} else {
+			raw[key] = value
+		}
 	}
 
 	return &mapBasedProperties{
@@ -87,7 +97,7 @@ func (config *mapBasedProperties) SetInt(key string, value int) {
 	config.lock.Unlock()
 }
 
-// Dumps the configuration internal map into a string.
+// ToString dumps the configuration internal map into a string.
 func (config *mapBasedProperties) ToString() string {
 	config.lock.RLock()
 	ret := fmt.Sprintf("%s", config.properties)
@@ -96,12 +106,12 @@ func (config *mapBasedProperties) ToString() string {
 	return ret
 }
 
-// Returns the error message.
+// Error returns the error message.
 func (configError *PropertyError) Error() string {
 	return configError.message
 }
 
-// Builds a new properties configuration structure
+// NewProperties builds a new properties configuration structure.
 func NewProperties() Properties {
 	return &mapBasedProperties{
 		properties: make(map[string]string),

core/conf/properties_test.go

@@ -24,6 +24,53 @@ func TestProperties(t *testing.T) {
 	assert.Equal(t, "test", props.GetString("app.name"))
 	assert.Equal(t, "app", props.GetString("app.program"))
 	assert.Equal(t, 5, props.GetInt("app.threads"))
+
+	val := props.ToString()
+	assert.Contains(t, val, "app.name")
+	assert.Contains(t, val, "app.program")
+	assert.Contains(t, val, "app.threads")
+}
+
+func TestPropertiesEnv(t *testing.T) {
+	text := `app.name = test
+
+    app.program=app
+
+	app.env1 = ${FOO}
+	app.env2 = $none
+
+    # this is comment
+    app.threads = 5`
+	tmpfile, err := fs.TempFilenameWithText(text)
+	assert.Nil(t, err)
+	defer os.Remove(tmpfile)
+
+	os.Setenv("FOO", "2")
+	defer os.Unsetenv("FOO")
+
+	props, err := LoadProperties(tmpfile, UseEnv())
+	assert.Nil(t, err)
+	assert.Equal(t, "test", props.GetString("app.name"))
+	assert.Equal(t, "app", props.GetString("app.program"))
+	assert.Equal(t, 5, props.GetInt("app.threads"))
+	assert.Equal(t, "2", props.GetString("app.env1"))
+	assert.Equal(t, "", props.GetString("app.env2"))
+
+	val := props.ToString()
+	assert.Contains(t, val, "app.name")
+	assert.Contains(t, val, "app.program")
+	assert.Contains(t, val, "app.threads")
+	assert.Contains(t, val, "app.env1")
+	assert.Contains(t, val, "app.env2")
+}
+
+func TestLoadProperties_badContent(t *testing.T) {
+	filename, err := fs.TempFilenameWithText("hello")
+	assert.Nil(t, err)
+	defer os.Remove(filename)
+	_, err = LoadProperties(filename)
+	assert.NotNil(t, err)
+	assert.True(t, len(err.Error()) > 0)
 }
 
 func TestSetString(t *testing.T) {
@@ -41,3 +88,8 @@ func TestSetInt(t *testing.T) {
 	props.SetInt(key, value)
 	assert.Equal(t, value, props.GetInt(key))
 }
+
+func TestLoadBadFile(t *testing.T) {
+	_, err := LoadProperties("nosuchfile")
+	assert.NotNil(t, err)
+}

core/contextx/deadline.go

@@ -1,17 +0,0 @@
-package contextx
-
-import (
-	"context"
-	"time"
-)
-
-func ShrinkDeadline(ctx context.Context, timeout time.Duration) (context.Context, func()) {
-	if deadline, ok := ctx.Deadline(); ok {
-		leftTime := time.Until(deadline)
-		if leftTime < timeout {
-			timeout = leftTime
-		}
-	}
-
-	return context.WithDeadline(ctx, time.Now().Add(timeout))
-}

core/contextx/deadline_test.go

@@ -1,27 +0,0 @@
-package contextx
-
-import (
-	"context"
-	"testing"
-	"time"
-
-	"github.com/stretchr/testify/assert"
-)
-
-func TestShrinkDeadlineLess(t *testing.T) {
-	deadline := time.Now().Add(time.Second)
-	ctx, _ := context.WithDeadline(context.Background(), deadline)
-	ctx, _ = ShrinkDeadline(ctx, time.Minute)
-	dl, ok := ctx.Deadline()
-	assert.True(t, ok)
-	assert.Equal(t, deadline, dl)
-}
-
-func TestShrinkDeadlineMore(t *testing.T) {
-	deadline := time.Now().Add(time.Minute)
-	ctx, _ := context.WithDeadline(context.Background(), deadline)
-	ctx, _ = ShrinkDeadline(ctx, time.Second)
-	dl, ok := ctx.Deadline()
-	assert.True(t, ok)
-	assert.True(t, dl.Before(deadline))
-}

core/contextx/unmarshaler.go

@@ -19,6 +19,7 @@ func (cv contextValuer) Value(key string) (interface{}, bool) {
 	return v, v != nil
 }
 
+// For unmarshals ctx into v.
 func For(ctx context.Context, v interface{}) error {
 	return unmarshaler.UnmarshalValuer(contextValuer{
 		Context: ctx,

core/contextx/unmarshaler_test.go

@@ -47,9 +47,11 @@ func TestUnmarshalContextWithMissing(t *testing.T) {
 		Name string `ctx:"name"`
 		Age  int    `ctx:"age"`
 	}
+	type name string
+	const PersonNameKey name = "name"
 
 	ctx := context.Background()
-	ctx = context.WithValue(ctx, "name", "kevin")
+	ctx = context.WithValue(ctx, PersonNameKey, "kevin")
 
 	var person Person
 	err := For(ctx, &person)

core/contextx/valueonlycontext.go

@@ -21,6 +21,7 @@ func (valueOnlyContext) Err() error {
 	return nil
 }
 
+// ValueOnlyFrom takes all values from the given ctx, without deadline and error control.
 func ValueOnlyFrom(ctx context.Context) context.Context {
 	return valueOnlyContext{
 		Context: ctx,

core/contextx/valueonlycontext_test.go

@@ -9,10 +9,13 @@ import (
 )
 
 func TestContextCancel(t *testing.T) {
-	c := context.WithValue(context.Background(), "key", "value")
+	type key string
+	var nameKey key = "name"
+	c := context.WithValue(context.Background(), nameKey, "value")
 	c1, cancel := context.WithCancel(c)
 	o := ValueOnlyFrom(c1)
-	c2, _ := context.WithCancel(o)
+	c2, cancel2 := context.WithCancel(o)
+	defer cancel2()
 	contexts := []context.Context{c1, c2}
 
 	for _, c := range contexts {
@@ -34,8 +37,9 @@ func TestContextCancel(t *testing.T) {
 	assert.NotEqual(t, context.Canceled, c2.Err())
 }
 
-func TestConextDeadline(t *testing.T) {
-	c, _ := context.WithDeadline(context.Background(), time.Now().Add(10*time.Millisecond))
+func TestContextDeadline(t *testing.T) {
+	c, cancel := context.WithDeadline(context.Background(), time.Now().Add(10*time.Millisecond))
+	cancel()
 	o := ValueOnlyFrom(c)
 	select {
 	case <-time.After(100 * time.Millisecond):
@@ -43,9 +47,11 @@ func TestConextDeadline(t *testing.T) {
 		t.Fatal("ValueOnlyContext: context should not have timed out")
 	}
 
-	c, _ = context.WithDeadline(context.Background(), time.Now().Add(10*time.Millisecond))
+	c, cancel = context.WithDeadline(context.Background(), time.Now().Add(10*time.Millisecond))
+	cancel()
 	o = ValueOnlyFrom(c)
-	c, _ = context.WithDeadline(o, time.Now().Add(20*time.Millisecond))
+	c, cancel = context.WithDeadline(o, time.Now().Add(20*time.Millisecond))
+	defer cancel()
 	select {
 	case <-time.After(100 * time.Millisecond):
 		t.Fatal("ValueOnlyContext+Deadline: context should have timed out")

core/discov/clients.go

@@ -8,12 +8,13 @@ import (
 )
 
 const (
-	indexOfKey = iota
+	_ = iota
 	indexOfId
 )
 
 const timeToLive int64 = 10
 
+// TimeToLive is seconds to live in etcd.
 var TimeToLive = timeToLive
 
 func extract(etcdKey string, index int) (string, bool) {

core/discov/clients_test.go

@@ -28,6 +28,9 @@ func TestExtract(t *testing.T) {
 
 	_, ok = extract("any", -1)
 	assert.False(t, ok)
+
+	_, ok = extract("any", 10)
+	assert.False(t, ok)
 }
 
 func TestMakeKey(t *testing.T) {

core/discov/config.go

@@ -2,11 +2,13 @@ package discov
 
 import "errors"
 
+// EtcdConf is the config item with the given key on etcd.
 type EtcdConf struct {
 	Hosts []string
 	Key   string
 }
 
+// Validate validates c.
 func (c EtcdConf) Validate() error {
 	if len(c.Hosts) == 0 {
 		return errors.New("empty etcd hosts")

core/discov/facade.go

@@ -1,47 +0,0 @@
-package discov
-
-import (
-	"github.com/tal-tech/go-zero/core/discov/internal"
-	"github.com/tal-tech/go-zero/core/lang"
-)
-
-type (
-	Facade struct {
-		endpoints []string
-		registry  *internal.Registry
-	}
-
-	FacadeListener interface {
-		OnAdd(key, val string)
-		OnDelete(key string)
-	}
-)
-
-func NewFacade(endpoints []string) Facade {
-	return Facade{
-		endpoints: endpoints,
-		registry:  internal.GetRegistry(),
-	}
-}
-
-func (f Facade) Client() internal.EtcdClient {
-	conn, err := f.registry.GetConn(f.endpoints)
-	lang.Must(err)
-	return conn
-}
-
-func (f Facade) Monitor(key string, l FacadeListener) {
-	f.registry.Monitor(f.endpoints, key, listenerAdapter{l})
-}
-
-type listenerAdapter struct {
-	l FacadeListener
-}
-
-func (la listenerAdapter) OnAdd(kv internal.KV) {
-	la.l.OnAdd(kv.Key, kv.Val)
-}
-
-func (la listenerAdapter) OnDelete(kv internal.KV) {
-	la.l.OnDelete(kv.Key)
-}

core/discov/internal/etcdclient.go

@@ -1,13 +1,15 @@
 //go:generate mockgen -package internal -destination etcdclient_mock.go -source etcdclient.go EtcdClient
+
 package internal
 
 import (
 	"context"
 
-	"go.etcd.io/etcd/clientv3"
+	clientv3 "go.etcd.io/etcd/client/v3"
 	"google.golang.org/grpc"
 )
 
+// EtcdClient interface represents an etcd client.
 type EtcdClient interface {
 	ActiveConnection() *grpc.ClientConn
 	Close() error

core/discov/internal/etcdclient_mock.go

@@ -6,10 +6,11 @@ package internal
 
 import (
 	context "context"
-	gomock "github.com/golang/mock/gomock"
-	clientv3 "go.etcd.io/etcd/clientv3"
-	grpc "google.golang.org/grpc"
 	reflect "reflect"
+
+	gomock "github.com/golang/mock/gomock"
+	clientv3 "go.etcd.io/etcd/client/v3"
+	grpc "google.golang.org/grpc"
 )
 
 // MockEtcdClient is a mock of EtcdClient interface

core/discov/internal/listener.go

@@ -1,6 +1,6 @@
-//go:generate mockgen -package internal -destination listener_mock.go -source listener.go Listener
 package internal
 
+// Listener interface wraps the OnUpdate method.
 type Listener interface {
-	OnUpdate(keys []string, values []string, newKey string)
+	OnUpdate(keys, values []string, newKey string)
 }

core/discov/internal/listener_mock.go

@@ -1,45 +0,0 @@
-// Code generated by MockGen. DO NOT EDIT.
-// Source: listener.go
-
-// Package internal is a generated GoMock package.
-package internal
-
-import (
-	gomock "github.com/golang/mock/gomock"
-	reflect "reflect"
-)
-
-// MockListener is a mock of Listener interface
-type MockListener struct {
-	ctrl     *gomock.Controller
-	recorder *MockListenerMockRecorder
-}
-
-// MockListenerMockRecorder is the mock recorder for MockListener
-type MockListenerMockRecorder struct {
-	mock *MockListener
-}
-
-// NewMockListener creates a new mock instance
-func NewMockListener(ctrl *gomock.Controller) *MockListener {
-	mock := &MockListener{ctrl: ctrl}
-	mock.recorder = &MockListenerMockRecorder{mock}
-	return mock
-}
-
-// EXPECT returns an object that allows the caller to indicate expected use
-func (m *MockListener) EXPECT() *MockListenerMockRecorder {
-	return m.recorder
-}
-
-// OnUpdate mocks base method
-func (m *MockListener) OnUpdate(keys, values []string, newKey string) {
-	m.ctrl.T.Helper()
-	m.ctrl.Call(m, "OnUpdate", keys, values, newKey)
-}
-
-// OnUpdate indicates an expected call of OnUpdate
-func (mr *MockListenerMockRecorder) OnUpdate(keys, values, newKey interface{}) *gomock.Call {
-	mr.mock.ctrl.T.Helper()
-	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "OnUpdate", reflect.TypeOf((*MockListener)(nil).OnUpdate), keys, values, newKey)
-}

core/discov/internal/registry.go

@@ -14,23 +14,35 @@ import (
 	"github.com/tal-tech/go-zero/core/logx"
 	"github.com/tal-tech/go-zero/core/syncx"
 	"github.com/tal-tech/go-zero/core/threading"
-	"go.etcd.io/etcd/clientv3"
+	clientv3 "go.etcd.io/etcd/client/v3"
 )
 
 var (
-	registryInstance = Registry{
+	registry = Registry{
 		clusters: make(map[string]*cluster),
 	}
 	connManager = syncx.NewResourceManager()
 )
 
+// A Registry is a registry that manages the etcd client connections.
 type Registry struct {
 	clusters map[string]*cluster
 	lock     sync.Mutex
 }
 
+// GetRegistry returns a global Registry.
 func GetRegistry() *Registry {
-	return &registryInstance
+	return &registry
+}
+
+// GetConn returns an etcd client connection associated with given endpoints.
+func (r *Registry) GetConn(endpoints []string) (EtcdClient, error) {
+	return r.getCluster(endpoints).getClient()
+}
+
+// Monitor monitors the key on given etcd endpoints, notify with the given UpdateListener.
+func (r *Registry) Monitor(endpoints []string, key string, l UpdateListener) error {
+	return r.getCluster(endpoints).monitor(key, l)
 }
 
 func (r *Registry) getCluster(endpoints []string) *cluster {
@@ -46,14 +58,6 @@ func (r *Registry) getCluster(endpoints []string) *cluster {
 	return c
 }
 
-func (r *Registry) GetConn(endpoints []string) (EtcdClient, error) {
-	return r.getCluster(endpoints).getClient()
-}
-
-func (r *Registry) Monitor(endpoints []string, key string, l UpdateListener) error {
-	return r.getCluster(endpoints).monitor(key, l)
-}
-
 type cluster struct {
 	endpoints  []string
 	key        string
@@ -256,26 +260,34 @@ func (c *cluster) reload(cli EtcdClient) {
 }
 
 func (c *cluster) watch(cli EtcdClient, key string) {
+	for {
+		if c.watchStream(cli, key) {
+			return
+		}
+	}
+}
+
+func (c *cluster) watchStream(cli EtcdClient, key string) bool {
 	rch := cli.Watch(clientv3.WithRequireLeader(c.context(cli)), makeKeyPrefix(key), clientv3.WithPrefix())
 	for {
 		select {
 		case wresp, ok := <-rch:
 			if !ok {
 				logx.Error("etcd monitor chan has been closed")
-				return
+				return false
 			}
 			if wresp.Canceled {
-				logx.Error("etcd monitor chan has been canceled")
-				return
+				logx.Errorf("etcd monitor chan has been canceled, error: %v", wresp.Err())
+				return false
 			}
 			if wresp.Err() != nil {
 				logx.Error(fmt.Sprintf("etcd monitor chan error: %v", wresp.Err()))
-				return
+				return false
 			}
 
 			c.handleWatchEvents(key, wresp.Events)
 		case <-c.done:
-			return
+			return true
 		}
 	}
 }
@@ -288,6 +300,7 @@ func (c *cluster) watchConnState(cli EtcdClient) {
 	watcher.watch(cli.ActiveConnection())
 }
 
+// DialClient dials an etcd cluster with given endpoints.
 func DialClient(endpoints []string) (EtcdClient, error) {
 	return clientv3.New(clientv3.Config{
 		Endpoints:            endpoints,

core/discov/internal/registry_test.go

@@ -8,10 +8,11 @@ import (
 	"github.com/golang/mock/gomock"
 	"github.com/stretchr/testify/assert"
 	"github.com/tal-tech/go-zero/core/contextx"
+	"github.com/tal-tech/go-zero/core/lang"
 	"github.com/tal-tech/go-zero/core/logx"
 	"github.com/tal-tech/go-zero/core/stringx"
-	"go.etcd.io/etcd/clientv3"
-	"go.etcd.io/etcd/mvcc/mvccpb"
+	"go.etcd.io/etcd/api/v3/mvccpb"
+	clientv3 "go.etcd.io/etcd/client/v3"
 )
 
 var mockLock sync.Mutex
@@ -202,11 +203,13 @@ func TestClusterWatch_RespFailures(t *testing.T) {
 			restore := setMockClient(cli)
 			defer restore()
 			ch := make(chan clientv3.WatchResponse)
-			cli.EXPECT().Watch(gomock.Any(), "any/", gomock.Any()).Return(ch)
+			cli.EXPECT().Watch(gomock.Any(), "any/", gomock.Any()).Return(ch).AnyTimes()
 			cli.EXPECT().Ctx().Return(context.Background()).AnyTimes()
 			c := new(cluster)
+			c.done = make(chan lang.PlaceholderType)
 			go func() {
 				ch <- resp
+				close(c.done)
 			}()
 			c.watch(cli, "any")
 		})
@@ -220,11 +223,13 @@ func TestClusterWatch_CloseChan(t *testing.T) {
 	restore := setMockClient(cli)
 	defer restore()
 	ch := make(chan clientv3.WatchResponse)
-	cli.EXPECT().Watch(gomock.Any(), "any/", gomock.Any()).Return(ch)
+	cli.EXPECT().Watch(gomock.Any(), "any/", gomock.Any()).Return(ch).AnyTimes()
 	cli.EXPECT().Ctx().Return(context.Background()).AnyTimes()
 	c := new(cluster)
+	c.done = make(chan lang.PlaceholderType)
 	go func() {
 		close(ch)
+		close(c.done)
 	}()
 	c.watch(cli, "any")
 }

core/discov/internal/statewatcher.go

@@ -1,4 +1,5 @@
 //go:generate mockgen -package internal -destination statewatcher_mock.go -source statewatcher.go etcdConn
+
 package internal
 
 import (
@@ -18,7 +19,8 @@ type (
 		disconnected bool
 		currentState connectivity.State
 		listeners    []func()
-		lock         sync.Mutex
+		// lock only guards listeners, because only listens can be accessed by other goroutines.
+		lock sync.Mutex
 	}
 )
 
@@ -32,27 +34,33 @@ func (sw *stateWatcher) addListener(l func()) {
 	sw.lock.Unlock()
 }
 
+func (sw *stateWatcher) notifyListeners() {
+	sw.lock.Lock()
+	defer sw.lock.Unlock()
+
+	for _, l := range sw.listeners {
+		l()
+	}
+}
+
+func (sw *stateWatcher) updateState(conn etcdConn) {
+	sw.currentState = conn.GetState()
+	switch sw.currentState {
+	case connectivity.TransientFailure, connectivity.Shutdown:
+		sw.disconnected = true
+	case connectivity.Ready:
+		if sw.disconnected {
+			sw.disconnected = false
+			sw.notifyListeners()
+		}
+	}
+}
+
 func (sw *stateWatcher) watch(conn etcdConn) {
 	sw.currentState = conn.GetState()
 	for {
 		if conn.WaitForStateChange(context.Background(), sw.currentState) {
-			newState := conn.GetState()
-			sw.lock.Lock()
-			sw.currentState = newState
-
-			switch newState {
-			case connectivity.TransientFailure, connectivity.Shutdown:
-				sw.disconnected = true
-			case connectivity.Ready:
-				if sw.disconnected {
-					sw.disconnected = false
-					for _, l := range sw.listeners {
-						l()
-					}
-				}
-			}
-
-			sw.lock.Unlock()
+			sw.updateState(conn)
 		}
 	}
 }

core/discov/internal/updatelistener.go

@@ -1,12 +1,15 @@
 //go:generate mockgen -package internal -destination updatelistener_mock.go -source updatelistener.go UpdateListener
+
 package internal
 
 type (
+	// A KV is used to store an etcd entry with key and value.
 	KV struct {
 		Key string
 		Val string
 	}
 
+	// UpdateListener wraps the OnAdd and OnDelete methods.
 	UpdateListener interface {
 		OnAdd(kv KV)
 		OnDelete(kv KV)

core/discov/internal/vars.go

@@ -3,17 +3,22 @@ package internal
 import "time"
 
 const (
+	// Delimiter is a separator that separates the etcd path.
+	Delimiter = '/'
+
 	autoSyncInterval   = time.Minute
 	coolDownInterval   = time.Second
 	dialTimeout        = 5 * time.Second
 	dialKeepAliveTime  = 5 * time.Second
 	requestTimeout     = 3 * time.Second
-	Delimiter          = '/'
 	endpointsSeparator = ","
 )
 
 var (
-	DialTimeout    = dialTimeout
+	// DialTimeout is the dial timeout.
+	DialTimeout = dialTimeout
+	// RequestTimeout is the request timeout.
 	RequestTimeout = requestTimeout
-	NewClient      = DialClient
+	// NewClient is used to create etcd clients.
+	NewClient = DialClient
 )

core/discov/kubernetes/etcd-statefulset.yaml

@@ -0,0 +1,64 @@
+apiVersion: apps/v1
+kind: StatefulSet
+metadata:
+  name: "etcd"
+  namespace: discov
+  labels:
+    app: "etcd"
+spec:
+  serviceName: "etcd"
+  replicas: 5
+  template:
+    metadata:
+      name: "etcd"
+      labels:
+        app: "etcd"
+    spec:
+      volumes:
+      - name: etcd-pvc
+        persistentVolumeClaim:
+          claimName: etcd-pvc
+      containers:
+      - name: "etcd"
+        image: quay.io/coreos/etcd:latest
+        ports:
+        - containerPort: 2379
+          name: client
+        - containerPort: 2380
+          name: peer
+        env:
+        - name: CLUSTER_SIZE
+          value: "5"
+        - name: SET_NAME
+          value: "etcd"
+        - name: VOLNAME
+          valueFrom:
+            fieldRef:
+              apiVersion: v1
+              fieldPath: metadata.name
+        volumeMounts:
+        - name: etcd-pvc
+          mountPath: /var/lib/etcd
+          subPathExpr: $(VOLNAME)  # data mounted respectively in each pod
+        command:
+          - "/bin/sh"
+          - "-ecx"
+          - |
+
+            chmod 700 /var/lib/etcd
+
+            IP=$(hostname -i)
+            PEERS=""
+            for i in $(seq 0 $((${CLUSTER_SIZE} - 1))); do
+                PEERS="${PEERS}${PEERS:+,}${SET_NAME}-${i}=http://${SET_NAME}-${i}.${SET_NAME}:2380"
+            done
+            exec etcd --name ${HOSTNAME} \
+              --listen-peer-urls http://0.0.0.0:2380 \
+              --listen-client-urls http://0.0.0.0:2379 \
+              --advertise-client-urls http://${HOSTNAME}.${SET_NAME}.discov:2379 \
+              --initial-advertise-peer-urls http://${HOSTNAME}.${SET_NAME}:2380 \
+              --initial-cluster ${PEERS} \
+              --initial-cluster-state new \
+              --logger zap \
+              --data-dir /var/lib/etcd \
+              --auto-compaction-retention 1

core/discov/kubernetes/etcd.yaml

@@ -1,16 +1,16 @@
 apiVersion: v1
 kind: Service
 metadata:
-  name: discov
-  namespace: discovery
+  name: etcd
+  namespace: discov
 spec:
   ports:
-    - name: discov-port
+    - name: etcd-port
       port: 2379
       protocol: TCP
       targetPort: 2379
   selector:
-    app: discov
+    app: etcd
 
 ---
 
@@ -18,30 +18,31 @@ apiVersion: v1
 kind: Pod
 metadata:
   labels:
-    app: discov
-    discov_node: discov0
-  name: discov0
-  namespace: discovery
+    app: etcd
+    etcd_node: etcd0
+  name: etcd0
+  namespace: discov
 spec:
   containers:
     - command:
         - /usr/local/bin/etcd
         - --name
-        - discov0
+        - etcd0
         - --initial-advertise-peer-urls
-        - http://discov0:2380
+        - http://etcd0:2380
         - --listen-peer-urls
         - http://0.0.0.0:2380
         - --listen-client-urls
         - http://0.0.0.0:2379
         - --advertise-client-urls
-        - http://discov0:2379
+        - http://etcd0.discov:2379
         - --initial-cluster
-        - discov0=http://discov0:2380,discov1=http://discov1:2380,discov2=http://discov2:2380,discov3=http://discov3:2380,discov4=http://discov4:2380
+        - etcd0=http://etcd0:2380,etcd1=http://etcd1:2380,etcd2=http://etcd2:2380,etcd3=http://etcd3:2380,etcd4=http://etcd4:2380
         - --initial-cluster-state
         - new
-      image: registry-vpc.cn-hangzhou.aliyuncs.com/xapp/etcd:latest
-      name: discov0
+        - --auto-compaction-retention=1
+      image: quay.io/coreos/etcd:latest
+      name: etcd0
       ports:
         - containerPort: 2379
           name: client
@@ -49,8 +50,6 @@ spec:
         - containerPort: 2380
           name: server
           protocol: TCP
-  imagePullSecrets:
-    - name: aliyun
   affinity:
     podAntiAffinity:
       requiredDuringSchedulingIgnoredDuringExecution:
@@ -59,7 +58,7 @@ spec:
               - key: app
                 operator: In
                 values:
-                  - discov
+                  - etcd
           topologyKey: "kubernetes.io/hostname"
   restartPolicy: Always
 
@@ -69,9 +68,9 @@ apiVersion: v1
 kind: Service
 metadata:
   labels:
-    discov_node: discov0
-  name: discov0
-  namespace: discovery
+    etcd_node: etcd0
+  name: etcd0
+  namespace: discov
 spec:
   ports:
     - name: client
@@ -83,7 +82,7 @@ spec:
       protocol: TCP
       targetPort: 2380
   selector:
-    discov_node: discov0
+    etcd_node: etcd0
 
 ---
 
@@ -91,30 +90,31 @@ apiVersion: v1
 kind: Pod
 metadata:
   labels:
-    app: discov
-    discov_node: discov1
-  name: discov1
-  namespace: discovery
+    app: etcd
+    etcd_node: etcd1
+  name: etcd1
+  namespace: discov
 spec:
   containers:
     - command:
         - /usr/local/bin/etcd
         - --name
-        - discov1
+        - etcd1
         - --initial-advertise-peer-urls
-        - http://discov1:2380
+        - http://etcd1:2380
         - --listen-peer-urls
         - http://0.0.0.0:2380
         - --listen-client-urls
         - http://0.0.0.0:2379
         - --advertise-client-urls
-        - http://discov1:2379
+        - http://etcd1.discov:2379
         - --initial-cluster
-        - discov0=http://discov0:2380,discov1=http://discov1:2380,discov2=http://discov2:2380,discov3=http://discov3:2380,discov4=http://discov4:2380
+        - etcd0=http://etcd0:2380,etcd1=http://etcd1:2380,etcd2=http://etcd2:2380,etcd3=http://etcd3:2380,etcd4=http://etcd4:2380
         - --initial-cluster-state
         - new
-      image: registry-vpc.cn-hangzhou.aliyuncs.com/xapp/etcd:latest
-      name: discov1
+        - --auto-compaction-retention=1
+      image: quay.io/coreos/etcd:latest
+      name: etcd1
       ports:
         - containerPort: 2379
           name: client
@@ -122,8 +122,6 @@ spec:
         - containerPort: 2380
           name: server
           protocol: TCP
-  imagePullSecrets:
-    - name: aliyun
   affinity:
     podAntiAffinity:
       requiredDuringSchedulingIgnoredDuringExecution:
@@ -132,7 +130,7 @@ spec:
               - key: app
                 operator: In
                 values:
-                  - discov
+                  - etcd
           topologyKey: "kubernetes.io/hostname"
   restartPolicy: Always
 
@@ -142,9 +140,9 @@ apiVersion: v1
 kind: Service
 metadata:
   labels:
-    discov_node: discov1
-  name: discov1
-  namespace: discovery
+    etcd_node: etcd1
+  name: etcd1
+  namespace: discov
 spec:
   ports:
     - name: client
@@ -156,7 +154,7 @@ spec:
       protocol: TCP
       targetPort: 2380
   selector:
-    discov_node: discov1
+    etcd_node: etcd1
 
 ---
 
@@ -164,30 +162,31 @@ apiVersion: v1
 kind: Pod
 metadata:
   labels:
-    app: discov
-    discov_node: discov2
-  name: discov2
-  namespace: discovery
+    app: etcd
+    etcd_node: etcd2
+  name: etcd2
+  namespace: discov
 spec:
   containers:
     - command:
         - /usr/local/bin/etcd
         - --name
-        - discov2
+        - etcd2
         - --initial-advertise-peer-urls
-        - http://discov2:2380
+        - http://etcd2:2380
         - --listen-peer-urls
         - http://0.0.0.0:2380
         - --listen-client-urls
         - http://0.0.0.0:2379
         - --advertise-client-urls
-        - http://discov2:2379
+        - http://etcd2.discov:2379
         - --initial-cluster
-        - discov0=http://discov0:2380,discov1=http://discov1:2380,discov2=http://discov2:2380,discov3=http://discov3:2380,discov4=http://discov4:2380
+        - etcd0=http://etcd0:2380,etcd1=http://etcd1:2380,etcd2=http://etcd2:2380,etcd3=http://etcd3:2380,etcd4=http://etcd4:2380
         - --initial-cluster-state
         - new
-      image: registry-vpc.cn-hangzhou.aliyuncs.com/xapp/etcd:latest
-      name: discov2
+        - --auto-compaction-retention=1
+      image: quay.io/coreos/etcd:latest
+      name: etcd2
       ports:
         - containerPort: 2379
           name: client
@@ -195,8 +194,6 @@ spec:
         - containerPort: 2380
           name: server
           protocol: TCP
-  imagePullSecrets:
-    - name: aliyun
   affinity:
     podAntiAffinity:
       requiredDuringSchedulingIgnoredDuringExecution:
@@ -205,7 +202,7 @@ spec:
               - key: app
                 operator: In
                 values:
-                  - discov
+                  - etcd
           topologyKey: "kubernetes.io/hostname"
   restartPolicy: Always
 
@@ -215,9 +212,9 @@ apiVersion: v1
 kind: Service
 metadata:
   labels:
-    discov_node: discov2
-  name: discov2
-  namespace: discovery
+    etcd_node: etcd2
+  name: etcd2
+  namespace: discov
 spec:
   ports:
     - name: client
@@ -229,7 +226,7 @@ spec:
       protocol: TCP
       targetPort: 2380
   selector:
-    discov_node: discov2
+    etcd_node: etcd2
 
 ---
 
@@ -237,30 +234,31 @@ apiVersion: v1
 kind: Pod
 metadata:
   labels:
-    app: discov
-    discov_node: discov3
-  name: discov3
-  namespace: discovery
+    app: etcd
+    etcd_node: etcd3
+  name: etcd3
+  namespace: discov
 spec:
   containers:
     - command:
         - /usr/local/bin/etcd
         - --name
-        - discov3
+        - etcd3
         - --initial-advertise-peer-urls
-        - http://discov3:2380
+        - http://etcd3:2380
         - --listen-peer-urls
         - http://0.0.0.0:2380
         - --listen-client-urls
         - http://0.0.0.0:2379
         - --advertise-client-urls
-        - http://discov3:2379
+        - http://etcd3.discov:2379
         - --initial-cluster
-        - discov0=http://discov0:2380,discov1=http://discov1:2380,discov2=http://discov2:2380,discov3=http://discov3:2380,discov4=http://discov4:2380
+        - etcd0=http://etcd0:2380,etcd1=http://etcd1:2380,etcd2=http://etcd2:2380,etcd3=http://etcd3:2380,etcd4=http://etcd4:2380
         - --initial-cluster-state
         - new
-      image: registry-vpc.cn-hangzhou.aliyuncs.com/xapp/etcd:latest
-      name: discov3
+        - --auto-compaction-retention=1
+      image: quay.io/coreos/etcd:latest
+      name: etcd3
       ports:
         - containerPort: 2379
           name: client
@@ -268,8 +266,6 @@ spec:
         - containerPort: 2380
           name: server
           protocol: TCP
-  imagePullSecrets:
-    - name: aliyun
   affinity:
     podAntiAffinity:
       requiredDuringSchedulingIgnoredDuringExecution:
@@ -278,7 +274,7 @@ spec:
               - key: app
                 operator: In
                 values:
-                  - discov
+                  - etcd
           topologyKey: "kubernetes.io/hostname"
   restartPolicy: Always
 
@@ -288,9 +284,9 @@ apiVersion: v1
 kind: Service
 metadata:
   labels:
-    discov_node: discov3
-  name: discov3
-  namespace: discovery
+    etcd_node: etcd3
+  name: etcd3
+  namespace: discov
 spec:
   ports:
     - name: client
@@ -302,7 +298,7 @@ spec:
       protocol: TCP
       targetPort: 2380
   selector:
-    discov_node: discov3
+    etcd_node: etcd3
 
 ---
 
@@ -310,30 +306,31 @@ apiVersion: v1
 kind: Pod
 metadata:
   labels:
-    app: discov
-    discov_node: discov4
-  name: discov4
-  namespace: discovery
+    app: etcd
+    etcd_node: etcd4
+  name: etcd4
+  namespace: discov
 spec:
   containers:
     - command:
         - /usr/local/bin/etcd
         - --name
-        - discov4
+        - etcd4
         - --initial-advertise-peer-urls
-        - http://discov4:2380
+        - http://etcd4:2380
         - --listen-peer-urls
         - http://0.0.0.0:2380
         - --listen-client-urls
         - http://0.0.0.0:2379
         - --advertise-client-urls
-        - http://discov4:2379
+        - http://etcd4.discov:2379
         - --initial-cluster
-        - discov0=http://discov0:2380,discov1=http://discov1:2380,discov2=http://discov2:2380,discov3=http://discov3:2380,discov4=http://discov4:2380
+        - etcd0=http://etcd0:2380,etcd1=http://etcd1:2380,etcd2=http://etcd2:2380,etcd3=http://etcd3:2380,etcd4=http://etcd4:2380
         - --initial-cluster-state
         - new
-      image: registry-vpc.cn-hangzhou.aliyuncs.com/xapp/etcd:latest
-      name: discov4
+        - --auto-compaction-retention=1
+      image: quay.io/coreos/etcd:latest
+      name: etcd4
       ports:
         - containerPort: 2379
           name: client
@@ -341,8 +338,6 @@ spec:
         - containerPort: 2380
           name: server
           protocol: TCP
-  imagePullSecrets:
-    - name: aliyun
   affinity:
     podAntiAffinity:
       requiredDuringSchedulingIgnoredDuringExecution:
@@ -351,7 +346,7 @@ spec:
               - key: app
                 operator: In
                 values:
-                  - discov
+                  - etcd
           topologyKey: "kubernetes.io/hostname"
   restartPolicy: Always
 
@@ -361,9 +356,9 @@ apiVersion: v1
 kind: Service
 metadata:
   labels:
-    discov_node: discov4
-  name: discov4
-  namespace: discovery
+    etcd_node: etcd4
+  name: etcd4
+  namespace: discov
 spec:
   ports:
     - name: client
@@ -375,4 +370,4 @@ spec:
       protocol: TCP
       targetPort: 2380
   selector:
-    discov_node: discov4
+    etcd_node: etcd4

core/discov/publisher.go

@@ -7,12 +7,14 @@ import (
 	"github.com/tal-tech/go-zero/core/proc"
 	"github.com/tal-tech/go-zero/core/syncx"
 	"github.com/tal-tech/go-zero/core/threading"
-	"go.etcd.io/etcd/clientv3"
+	clientv3 "go.etcd.io/etcd/client/v3"
 )
 
 type (
+	// PublisherOption defines the method to customize a Publisher.
 	PublisherOption func(client *Publisher)
 
+	// A Publisher can be used to publish the value to an etcd cluster on the given key.
 	Publisher struct {
 		endpoints  []string
 		key        string
@@ -26,6 +28,10 @@ type (
 	}
 )
 
+// NewPublisher returns a Publisher.
+// endpoints is the hosts of the etcd cluster.
+// key:value are a pair to be published.
+// opts are used to customize the Publisher.
 func NewPublisher(endpoints []string, key, value string, opts ...PublisherOption) *Publisher {
 	publisher := &Publisher{
 		endpoints:  endpoints,
@@ -43,6 +49,7 @@ func NewPublisher(endpoints []string, key, value string, opts ...PublisherOption
 	return publisher
 }
 
+// KeepAlive keeps key:value alive.
 func (p *Publisher) KeepAlive() error {
 	cli, err := internal.GetRegistry().GetConn(p.endpoints)
 	if err != nil {
@@ -61,14 +68,17 @@ func (p *Publisher) KeepAlive() error {
 	return p.keepAliveAsync(cli)
 }
 
+// Pause pauses the renewing of key:value.
 func (p *Publisher) Pause() {
 	p.pauseChan <- lang.Placeholder
 }
 
+// Resume resumes the renewing of key:value.
 func (p *Publisher) Resume() {
 	p.resumeChan <- lang.Placeholder
 }
 
+// Stop stops the renewing and revokes the registration.
 func (p *Publisher) Stop() {
 	p.quit.Close()
 }
@@ -135,6 +145,7 @@ func (p *Publisher) revoke(cli internal.EtcdClient) {
 	}
 }
 
+// WithId customizes a Publisher with the id.
 func WithId(id int64) PublisherOption {
 	return func(publisher *Publisher) {
 		publisher.id = id

core/discov/publisher_test.go

@@ -4,12 +4,14 @@ import (
 	"errors"
 	"sync"
 	"testing"
+	"time"
 
 	"github.com/golang/mock/gomock"
 	"github.com/stretchr/testify/assert"
 	"github.com/tal-tech/go-zero/core/discov/internal"
+	"github.com/tal-tech/go-zero/core/lang"
 	"github.com/tal-tech/go-zero/core/logx"
-	"go.etcd.io/etcd/clientv3"
+	clientv3 "go.etcd.io/etcd/client/v3"
 )
 
 func init() {
@@ -111,6 +113,10 @@ func TestPublisher_keepAliveAsyncQuit(t *testing.T) {
 	defer ctrl.Finish()
 	const id clientv3.LeaseID = 1
 	cli := internal.NewMockEtcdClient(ctrl)
+	cli.EXPECT().ActiveConnection()
+	cli.EXPECT().Close()
+	defer cli.Close()
+	cli.ActiveConnection()
 	restore := setMockClient(cli)
 	defer restore()
 	cli.EXPECT().Ctx().AnyTimes()
@@ -148,3 +154,16 @@ func TestPublisher_keepAliveAsyncPause(t *testing.T) {
 	pub.Pause()
 	wg.Wait()
 }
+
+func TestPublisher_Resume(t *testing.T) {
+	publisher := new(Publisher)
+	publisher.resumeChan = make(chan lang.PlaceholderType)
+	go func() {
+		publisher.Resume()
+	}()
+	go func() {
+		time.Sleep(time.Minute)
+		t.Fail()
+	}()
+	<-publisher.resumeChan
+}

core/discov/subscriber.go

@@ -13,13 +13,19 @@ type (
 		exclusive bool
 	}
 
+	// SubOption defines the method to customize a Subscriber.
 	SubOption func(opts *subOptions)
 
+	// A Subscriber is used to subscribe the given key on a etcd cluster.
 	Subscriber struct {
 		items *container
 	}
 )
 
+// NewSubscriber returns a Subscriber.
+// endpoints is the hosts of the etcd cluster.
+// key is the key to subscribe.
+// opts are used to customize the Subscriber.
 func NewSubscriber(endpoints []string, key string, opts ...SubOption) (*Subscriber, error) {
 	var subOpts subOptions
 	for _, opt := range opts {
@@ -36,15 +42,17 @@ func NewSubscriber(endpoints []string, key string, opts ...SubOption) (*Subscrib
 	return sub, nil
 }
 
+// AddListener adds listener to s.
 func (s *Subscriber) AddListener(listener func()) {
 	s.items.addListener(listener)
 }
 
+// Values returns all the subscription values.
 func (s *Subscriber) Values() []string {
 	return s.items.getValues()
 }
 
-// exclusive means that key value can only be 1:1,
+// Exclusive means that key value can only be 1:1,
 // which means later added value will remove the keys associated with the same value previously.
 func Exclusive() SubOption {
 	return func(opts *subOptions) {
@@ -100,9 +108,9 @@ func (c *container) addKv(key, value string) ([]string, bool) {
 
 	if early {
 		return previous, true
-	} else {
-		return nil, false
 	}
+
+	return nil, false
 }
 
 func (c *container) addListener(listener func()) {

core/discov/subscriber_test.go

@@ -1,6 +1,7 @@
 package discov
 
 import (
+	"sync/atomic"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -198,3 +199,18 @@ func TestContainer(t *testing.T) {
 		}
 	}
 }
+
+func TestSubscriber(t *testing.T) {
+	var opt subOptions
+	Exclusive()(&opt)
+
+	sub := new(Subscriber)
+	sub.items = newContainer(opt.exclusive)
+	var count int32
+	sub.AddListener(func() {
+		atomic.AddInt32(&count, 1)
+	})
+	sub.items.notifyChange()
+	assert.Empty(t, sub.Values())
+	assert.Equal(t, int32(1), atomic.LoadInt32(&count))
+}

core/errorx/atomicerror.go

@@ -1,21 +1,21 @@
 package errorx
 
-import "sync"
+import "sync/atomic"
 
+// AtomicError defines an atomic error.
 type AtomicError struct {
-	err  error
-	lock sync.Mutex
+	err atomic.Value // error
 }
 
+// Set sets the error.
 func (ae *AtomicError) Set(err error) {
-	ae.lock.Lock()
-	ae.err = err
-	ae.lock.Unlock()
+	ae.err.Store(err)
 }
 
+// Load returns the error.
 func (ae *AtomicError) Load() error {
-	ae.lock.Lock()
-	err := ae.err
-	ae.lock.Unlock()
-	return err
+	if v := ae.err.Load(); v != nil {
+		return v.(error)
+	}
+	return nil
 }

core/errorx/atomicerror_test.go

@@ -2,6 +2,8 @@ package errorx
 
 import (
 	"errors"
+	"sync"
+	"sync/atomic"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -19,3 +21,53 @@ func TestAtomicErrorNil(t *testing.T) {
 	var err AtomicError
 	assert.Nil(t, err.Load())
 }
+
+func BenchmarkAtomicError(b *testing.B) {
+	var aerr AtomicError
+	wg := sync.WaitGroup{}
+
+	b.Run("Load", func(b *testing.B) {
+		var done uint32
+		go func() {
+			for {
+				if atomic.LoadUint32(&done) != 0 {
+					break
+				}
+				wg.Add(1)
+				go func() {
+					aerr.Set(errDummy)
+					wg.Done()
+				}()
+			}
+		}()
+		b.ResetTimer()
+		for i := 0; i < b.N; i++ {
+			_ = aerr.Load()
+		}
+		b.StopTimer()
+		atomic.StoreUint32(&done, 1)
+		wg.Wait()
+	})
+	b.Run("Set", func(b *testing.B) {
+		var done uint32
+		go func() {
+			for {
+				if atomic.LoadUint32(&done) != 0 {
+					break
+				}
+				wg.Add(1)
+				go func() {
+					_ = aerr.Load()
+					wg.Done()
+				}()
+			}
+		}()
+		b.ResetTimer()
+		for i := 0; i < b.N; i++ {
+			aerr.Set(errDummy)
+		}
+		b.StopTimer()
+		atomic.StoreUint32(&done, 1)
+		wg.Wait()
+	})
+}

core/errorx/batcherror.go

@@ -3,6 +3,7 @@ package errorx
 import "bytes"
 
 type (
+	// A BatchError is an error that can hold multiple errors.
 	BatchError struct {
 		errs errorArray
 	}
@@ -10,12 +11,14 @@ type (
 	errorArray []error
 )
 
+// Add adds err to be.
 func (be *BatchError) Add(err error) {
 	if err != nil {
 		be.errs = append(be.errs, err)
 	}
 }
 
+// Err returns an error that represents all errors.
 func (be *BatchError) Err() error {
 	switch len(be.errs) {
 	case 0:
@@ -27,10 +30,12 @@ func (be *BatchError) Err() error {
 	}
 }
 
+// NotNil checks if any error inside.
 func (be *BatchError) NotNil() bool {
 	return len(be.errs) > 0
 }
 
+// Error returns a string that represents inside errors.
 func (ea errorArray) Error() string {
 	var buf bytes.Buffer
 

core/errorx/callchain.go

@@ -0,0 +1,12 @@
+package errorx
+
+// Chain runs funs one by one until an error occurred.
+func Chain(fns ...func() error) error {
+	for _, fn := range fns {
+		if err := fn(); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}

core/errorx/callchain_test.go

@@ -0,0 +1,27 @@
+package errorx
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestChain(t *testing.T) {
+	errDummy := errors.New("dummy")
+	assert.Nil(t, Chain(func() error {
+		return nil
+	}, func() error {
+		return nil
+	}))
+	assert.Equal(t, errDummy, Chain(func() error {
+		return errDummy
+	}, func() error {
+		return nil
+	}))
+	assert.Equal(t, errDummy, Chain(func() error {
+		return nil
+	}, func() error {
+		return errDummy
+	}))
+}

core/executors/bulkexecutor.go

@@ -5,8 +5,12 @@ import "time"
 const defaultBulkTasks = 1000
 
 type (
+	// BulkOption defines the method to customize a BulkExecutor.
 	BulkOption func(options *bulkOptions)
 
+	// A BulkExecutor is an executor that can execute tasks on either requirement meets:
+	// 1. up to given size of tasks
+	// 2. flush interval time elapsed
 	BulkExecutor struct {
 		executor  *PeriodicalExecutor
 		container *bulkContainer
@@ -18,6 +22,7 @@ type (
 	}
 )
 
+// NewBulkExecutor returns a BulkExecutor.
 func NewBulkExecutor(execute Execute, opts ...BulkOption) *BulkExecutor {
 	options := newBulkOptions()
 	for _, opt := range opts {
@@ -36,25 +41,30 @@ func NewBulkExecutor(execute Execute, opts ...BulkOption) *BulkExecutor {
 	return executor
 }
 
+// Add adds task into be.
 func (be *BulkExecutor) Add(task interface{}) error {
 	be.executor.Add(task)
 	return nil
 }
 
+// Flush forces be to flush and execute tasks.
 func (be *BulkExecutor) Flush() {
 	be.executor.Flush()
 }
 
+// Wait waits be to done with the task execution.
 func (be *BulkExecutor) Wait() {
 	be.executor.Wait()
 }
 
+// WithBulkTasks customizes a BulkExecutor with given tasks limit.
 func WithBulkTasks(tasks int) BulkOption {
 	return func(options *bulkOptions) {
 		options.cachedTasks = tasks
 	}
 }
 
+// WithBulkInterval customizes a BulkExecutor with given flush interval.
 func WithBulkInterval(duration time.Duration) BulkOption {
 	return func(options *bulkOptions) {
 		options.flushInterval = duration

core/executors/bulkexecutor_test.go

@@ -12,14 +12,14 @@ func TestBulkExecutor(t *testing.T) {
 	var values []int
 	var lock sync.Mutex
 
-	exeutor := NewBulkExecutor(func(items []interface{}) {
+	executor := NewBulkExecutor(func(items []interface{}) {
 		lock.Lock()
 		values = append(values, len(items))
 		lock.Unlock()
 	}, WithBulkTasks(10), WithBulkInterval(time.Minute))
 
 	for i := 0; i < 50; i++ {
-		exeutor.Add(1)
+		executor.Add(1)
 		time.Sleep(time.Millisecond)
 	}
 
@@ -40,13 +40,13 @@ func TestBulkExecutorFlushInterval(t *testing.T) {
 	var wait sync.WaitGroup
 
 	wait.Add(1)
-	exeutor := NewBulkExecutor(func(items []interface{}) {
+	executor := NewBulkExecutor(func(items []interface{}) {
 		assert.Equal(t, size, len(items))
 		wait.Done()
 	}, WithBulkTasks(caches), WithBulkInterval(time.Millisecond*100))
 
 	for i := 0; i < size; i++ {
-		exeutor.Add(1)
+		executor.Add(1)
 	}
 
 	wait.Wait()
@@ -86,9 +86,7 @@ func TestBuldExecutorFlushSlowTasks(t *testing.T) {
 		time.Sleep(time.Millisecond * 100)
 		lock.Lock()
 		defer lock.Unlock()
-		for _, i := range tasks {
-			result = append(result, i)
-		}
+		result = append(result, tasks...)
 	}, WithBulkTasks(1000))
 	for i := 0; i < total; i++ {
 		assert.Nil(t, exec.Add(i))

core/executors/chunkexecutor.go

@@ -5,8 +5,12 @@ import "time"
 const defaultChunkSize = 1024 * 1024 // 1M
 
 type (
+	// ChunkOption defines the method to customize a ChunkExecutor.
 	ChunkOption func(options *chunkOptions)
 
+	// A ChunkExecutor is an executor to execute tasks when either requirement meets:
+	// 1. up to given chunk size
+	// 2. flush interval elapsed
 	ChunkExecutor struct {
 		executor  *PeriodicalExecutor
 		container *chunkContainer
@@ -18,6 +22,7 @@ type (
 	}
 )
 
+// NewChunkExecutor returns a ChunkExecutor.
 func NewChunkExecutor(execute Execute, opts ...ChunkOption) *ChunkExecutor {
 	options := newChunkOptions()
 	for _, opt := range opts {
@@ -36,6 +41,7 @@ func NewChunkExecutor(execute Execute, opts ...ChunkOption) *ChunkExecutor {
 	return executor
 }
 
+// Add adds task with given chunk size into ce.
 func (ce *ChunkExecutor) Add(task interface{}, size int) error {
 	ce.executor.Add(chunk{
 		val:  task,
@@ -44,20 +50,24 @@ func (ce *ChunkExecutor) Add(task interface{}, size int) error {
 	return nil
 }
 
+// Flush forces ce to flush and execute tasks.
 func (ce *ChunkExecutor) Flush() {
 	ce.executor.Flush()
 }
 
+// Wait waits the execution to be done.
 func (ce *ChunkExecutor) Wait() {
 	ce.executor.Wait()
 }
 
+// WithChunkBytes customizes a ChunkExecutor with the given chunk size.
 func WithChunkBytes(size int) ChunkOption {
 	return func(options *chunkOptions) {
 		options.chunkSize = size
 	}
 }
 
+// WithFlushInterval customizes a ChunkExecutor with the given flush interval.
 func WithFlushInterval(duration time.Duration) ChunkOption {
 	return func(options *chunkOptions) {
 		options.flushInterval = duration

core/executors/chunkexecutor_test.go

@@ -12,14 +12,14 @@ func TestChunkExecutor(t *testing.T) {
 	var values []int
 	var lock sync.Mutex
 
-	exeutor := NewChunkExecutor(func(items []interface{}) {
+	executor := NewChunkExecutor(func(items []interface{}) {
 		lock.Lock()
 		values = append(values, len(items))
 		lock.Unlock()
 	}, WithChunkBytes(10), WithFlushInterval(time.Minute))
 
 	for i := 0; i < 50; i++ {
-		exeutor.Add(1, 1)
+		executor.Add(1, 1)
 		time.Sleep(time.Millisecond)
 	}
 
@@ -40,13 +40,13 @@ func TestChunkExecutorFlushInterval(t *testing.T) {
 	var wait sync.WaitGroup
 
 	wait.Add(1)
-	exeutor := NewChunkExecutor(func(items []interface{}) {
+	executor := NewChunkExecutor(func(items []interface{}) {
 		assert.Equal(t, size, len(items))
 		wait.Done()
 	}, WithChunkBytes(caches), WithFlushInterval(time.Millisecond*100))
 
 	for i := 0; i < size; i++ {
-		exeutor.Add(1, 1)
+		executor.Add(1, 1)
 	}
 
 	wait.Wait()

core/executors/delayexecutor.go

@@ -7,6 +7,7 @@ import (
 	"github.com/tal-tech/go-zero/core/threading"
 )
 
+// A DelayExecutor delays a tasks on given delay interval.
 type DelayExecutor struct {
 	fn        func()
 	delay     time.Duration
@@ -14,6 +15,7 @@ type DelayExecutor struct {
 	lock      sync.Mutex
 }
 
+// NewDelayExecutor returns a DelayExecutor with given fn and delay.
 func NewDelayExecutor(fn func(), delay time.Duration) *DelayExecutor {
 	return &DelayExecutor{
 		fn:    fn,
@@ -21,6 +23,7 @@ func NewDelayExecutor(fn func(), delay time.Duration) *DelayExecutor {
 	}
 }
 
+// Trigger triggers the task to be executed after given delay, safe to trigger more than once.
 func (de *DelayExecutor) Trigger() {
 	de.lock.Lock()
 	defer de.lock.Unlock()

core/executors/lessexecutor.go

@@ -7,11 +7,13 @@ import (
 	"github.com/tal-tech/go-zero/core/timex"
 )
 
+// A LessExecutor is an executor to limit execution once within given time interval.
 type LessExecutor struct {
 	threshold time.Duration
 	lastTime  *syncx.AtomicDuration
 }
 
+// NewLessExecutor returns a LessExecutor with given threshold as time interval.
 func NewLessExecutor(threshold time.Duration) *LessExecutor {
 	return &LessExecutor{
 		threshold: threshold,
@@ -19,6 +21,8 @@ func NewLessExecutor(threshold time.Duration) *LessExecutor {
 	}
 }
 
+// DoOrDiscard executes or discards the task depends on if
+// another task was executed within the time interval.
 func (le *LessExecutor) DoOrDiscard(execute func()) bool {
 	now := timex.Now()
 	lastTime := le.lastTime.Load()

core/executors/periodicalexecutor.go

@@ -3,8 +3,10 @@ package executors
 import (
 	"reflect"
 	"sync"
+	"sync/atomic"
 	"time"
 
+	"github.com/tal-tech/go-zero/core/lang"
 	"github.com/tal-tech/go-zero/core/proc"
 	"github.com/tal-tech/go-zero/core/syncx"
 	"github.com/tal-tech/go-zero/core/threading"
@@ -14,7 +16,7 @@ import (
 const idleRound = 10
 
 type (
-	// A type that satisfies executors.TaskContainer can be used as the underlying
+	// TaskContainer interface defines a type that can be used as the underlying
 	// container that used to do periodical executions.
 	TaskContainer interface {
 		// AddTask adds the task into the container.
@@ -26,27 +28,32 @@ type (
 		RemoveAll() interface{}
 	}
 
+	// A PeriodicalExecutor is an executor that periodically execute tasks.
 	PeriodicalExecutor struct {
 		commander chan interface{}
 		interval  time.Duration
 		container TaskContainer
 		waitGroup sync.WaitGroup
 		// avoid race condition on waitGroup when calling wg.Add/Done/Wait(...)
-		wgBarrier syncx.Barrier
-		guarded   bool
-		newTicker func(duration time.Duration) timex.Ticker
-		lock      sync.Mutex
+		wgBarrier   syncx.Barrier
+		confirmChan chan lang.PlaceholderType
+		inflight    int32
+		guarded     bool
+		newTicker   func(duration time.Duration) timex.Ticker
+		lock        sync.Mutex
 	}
 )
 
+// NewPeriodicalExecutor returns a PeriodicalExecutor with given interval and container.
 func NewPeriodicalExecutor(interval time.Duration, container TaskContainer) *PeriodicalExecutor {
 	executor := &PeriodicalExecutor{
 		// buffer 1 to let the caller go quickly
-		commander: make(chan interface{}, 1),
-		interval:  interval,
-		container: container,
+		commander:   make(chan interface{}, 1),
+		interval:    interval,
+		container:   container,
+		confirmChan: make(chan lang.PlaceholderType),
 		newTicker: func(d time.Duration) timex.Ticker {
-			return timex.NewTicker(interval)
+			return timex.NewTicker(d)
 		},
 	}
 	proc.AddShutdownListener(func() {
@@ -56,13 +63,17 @@ func NewPeriodicalExecutor(interval time.Duration, container TaskContainer) *Per
 	return executor
 }
 
+// Add adds tasks into pe.
 func (pe *PeriodicalExecutor) Add(task interface{}) {
 	if vals, ok := pe.addAndCheck(task); ok {
 		pe.commander <- vals
+		<-pe.confirmChan
 	}
 }
 
+// Flush forces pe to execute tasks.
 func (pe *PeriodicalExecutor) Flush() bool {
+	pe.enterExecution()
 	return pe.executeTasks(func() interface{} {
 		pe.lock.Lock()
 		defer pe.lock.Unlock()
@@ -70,13 +81,16 @@ func (pe *PeriodicalExecutor) Flush() bool {
 	}())
 }
 
+// Sync lets caller to run fn thread-safe with pe, especially for the underlying container.
 func (pe *PeriodicalExecutor) Sync(fn func()) {
 	pe.lock.Lock()
 	defer pe.lock.Unlock()
 	fn()
 }
 
+// Wait waits the execution to be done.
 func (pe *PeriodicalExecutor) Wait() {
+	pe.Flush()
 	pe.wgBarrier.Guard(func() {
 		pe.waitGroup.Wait()
 	})
@@ -85,18 +99,16 @@ func (pe *PeriodicalExecutor) Wait() {
 func (pe *PeriodicalExecutor) addAndCheck(task interface{}) (interface{}, bool) {
 	pe.lock.Lock()
 	defer func() {
-		var start bool
 		if !pe.guarded {
 			pe.guarded = true
-			start = true
+			// defer to unlock quickly
+			defer pe.backgroundFlush()
 		}
 		pe.lock.Unlock()
-		if start {
-			pe.backgroundFlush()
-		}
 	}()
 
 	if pe.container.AddTask(task) {
+		atomic.AddInt32(&pe.inflight, 1)
 		return pe.container.RemoveAll(), true
 	}
 
@@ -105,6 +117,9 @@ func (pe *PeriodicalExecutor) addAndCheck(task interface{}) (interface{}, bool)
 
 func (pe *PeriodicalExecutor) backgroundFlush() {
 	threading.GoSafe(func() {
+		// flush before quit goroutine to avoid missing tasks
+		defer pe.Flush()
+
 		ticker := pe.newTicker(pe.interval)
 		defer ticker.Stop()
 
@@ -114,6 +129,9 @@ func (pe *PeriodicalExecutor) backgroundFlush() {
 			select {
 			case vals := <-pe.commander:
 				commanded = true
+				atomic.AddInt32(&pe.inflight, -1)
+				pe.enterExecution()
+				pe.confirmChan <- lang.Placeholder
 				pe.executeTasks(vals)
 				last = timex.Now()
 			case <-ticker.Chan():
@@ -121,13 +139,7 @@ func (pe *PeriodicalExecutor) backgroundFlush() {
 					commanded = false
 				} else if pe.Flush() {
 					last = timex.Now()
-				} else if timex.Since(last) > pe.interval*idleRound {
-					pe.lock.Lock()
-					pe.guarded = false
-					pe.lock.Unlock()
-
-					// flush again to avoid missing tasks
-					pe.Flush()
+				} else if pe.shallQuit(last) {
 					return
 				}
 			}
@@ -135,13 +147,18 @@ func (pe *PeriodicalExecutor) backgroundFlush() {
 	})
 }
 
-func (pe *PeriodicalExecutor) executeTasks(tasks interface{}) bool {
+func (pe *PeriodicalExecutor) doneExecution() {
+	pe.waitGroup.Done()
+}
+
+func (pe *PeriodicalExecutor) enterExecution() {
 	pe.wgBarrier.Guard(func() {
 		pe.waitGroup.Add(1)
 	})
-	defer pe.wgBarrier.Guard(func() {
-		pe.waitGroup.Done()
-	})
+}
+
+func (pe *PeriodicalExecutor) executeTasks(tasks interface{}) bool {
+	defer pe.doneExecution()
 
 	ok := pe.hasTasks(tasks)
 	if ok {
@@ -165,3 +182,19 @@ func (pe *PeriodicalExecutor) hasTasks(tasks interface{}) bool {
 		return true
 	}
 }
+
+func (pe *PeriodicalExecutor) shallQuit(last time.Duration) (stop bool) {
+	if timex.Since(last) <= pe.interval*idleRound {
+		return
+	}
+
+	// checking pe.inflight and setting pe.guarded should be locked together
+	pe.lock.Lock()
+	if atomic.LoadInt32(&pe.inflight) == 0 {
+		pe.guarded = false
+		stop = true
+	}
+	pe.lock.Unlock()
+
+	return
+}

core/executors/periodicalexecutor_test.go

@@ -106,6 +106,60 @@ func TestPeriodicalExecutor_Bulk(t *testing.T) {
 	lock.Unlock()
 }
 
+func TestPeriodicalExecutor_Wait(t *testing.T) {
+	var lock sync.Mutex
+	executer := NewBulkExecutor(func(tasks []interface{}) {
+		lock.Lock()
+		defer lock.Unlock()
+		time.Sleep(10 * time.Millisecond)
+	}, WithBulkTasks(1), WithBulkInterval(time.Second))
+	for i := 0; i < 10; i++ {
+		executer.Add(1)
+	}
+	executer.Flush()
+	executer.Wait()
+}
+
+func TestPeriodicalExecutor_WaitFast(t *testing.T) {
+	const total = 3
+	var cnt int
+	var lock sync.Mutex
+	executer := NewBulkExecutor(func(tasks []interface{}) {
+		defer func() {
+			cnt++
+		}()
+		lock.Lock()
+		defer lock.Unlock()
+		time.Sleep(10 * time.Millisecond)
+	}, WithBulkTasks(1), WithBulkInterval(10*time.Millisecond))
+	for i := 0; i < total; i++ {
+		executer.Add(2)
+	}
+	executer.Flush()
+	executer.Wait()
+	assert.Equal(t, total, cnt)
+}
+
+func TestPeriodicalExecutor_Deadlock(t *testing.T) {
+	executor := NewBulkExecutor(func(tasks []interface{}) {
+	}, WithBulkTasks(1), WithBulkInterval(time.Millisecond))
+	for i := 0; i < 1e5; i++ {
+		executor.Add(1)
+	}
+}
+
+func TestPeriodicalExecutor_hasTasks(t *testing.T) {
+	ticker := timex.NewFakeTicker()
+	defer ticker.Stop()
+
+	exec := NewPeriodicalExecutor(time.Millisecond, newContainer(time.Millisecond, nil))
+	exec.newTicker = func(d time.Duration) timex.Ticker {
+		return ticker
+	}
+	assert.False(t, exec.hasTasks(nil))
+	assert.True(t, exec.hasTasks(1))
+}
+
 // go test -benchtime 10s -bench .
 func BenchmarkExecutor(b *testing.B) {
 	b.ReportAllocs()

core/executors/vars.go

@@ -4,4 +4,5 @@ import "time"
 
 const defaultFlushInterval = time.Second
 
+// Execute defines the method to execute tasks.
 type Execute func(tasks []interface{})

core/filex/file.go

@@ -7,6 +7,7 @@ import (
 
 const bufSize = 1024
 
+// FirstLine returns the first line of the file.
 func FirstLine(filename string) (string, error) {
 	file, err := os.Open(filename)
 	if err != nil {
@@ -17,6 +18,7 @@ func FirstLine(filename string) (string, error) {
 	return firstLine(file)
 }
 
+// LastLine returns the last line of the file.
 func LastLine(filename string) (string, error) {
 	file, err := os.Open(filename)
 	if err != nil {
@@ -69,11 +71,11 @@ func lastLine(filename string, file *os.File) (string, error) {
 
 		if buf[n-1] == '\n' {
 			buf = buf[:n-1]
-			n -= 1
+			n--
 		} else {
 			buf = buf[:n]
 		}
-		for n -= 1; n >= 0; n-- {
+		for n--; n >= 0; n-- {
 			if buf[n] == '\n' {
 				return string(append(buf[n+1:], last...)), nil
 			}

core/filex/file_test.go

@@ -4,9 +4,8 @@ import (
 	"os"
 	"testing"
 
-	"github.com/tal-tech/go-zero/core/fs"
-
 	"github.com/stretchr/testify/assert"
+	"github.com/tal-tech/go-zero/core/fs"
 )
 
 const (
@@ -15,34 +14,34 @@ const (
 	text          = `first line
 Cum sociis natoque penatibus et magnis dis parturient. Phasellus laoreet lorem vel dolor tempus vehicula. Vivamus sagittis lacus vel augue laoreet rutrum faucibus. Integer legentibus erat a ante historiarum dapibus.
 Quisque ut dolor gravida, placerat libero vel, euismod. Quam temere in vitiis, legem sancimus haerentia. Qui ipsorum lingua Celtae, nostra Galli appellantur. Quis aute iure reprehenderit in voluptate velit esse. Fabio vel iudice vincam, sunt in culpa qui officia. Cras mattis iudicium purus sit amet fermentum.
-Quo usque tandem abutere, Catilina, patientia nostra? Gallia est omnis divisa in partes tres, quarum. Quam diu etiam furor iste tuus nos eludet? Quid securi etiam tamquam eu fugiat nulla pariatur. Curabitur blandit tempus ardua ridiculus sed magna.
+Quo usque tandem abutere, Catilina, patientia nostra? Gallia est omnis divisa in partes tres, quarum. Quam diu etiam furor iste tuus nos eludet? Quid securi etiam tamquam eu fugiat nulla pariatur. Curabitur blandit tempus ardua ridiculous sed magna.
 Magna pars studiorum, prodita quaerimus. Cum ceteris in veneratione tui montes, nascetur mus. Morbi odio eros, volutpat ut pharetra vitae, lobortis sed nibh. Plura mihi bona sunt, inclinet, amari petere vellent. Idque Caesaris facere voluntate liceret: sese habere. Tu quoque, Brute, fili mi, nihil timor populi, nihil!
 Tityre, tu patulae recubans sub tegmine fagi dolor. Inmensae subtilitatis, obscuris et malesuada fames. Quae vero auctorem tractata ab fiducia dicuntur.
 Cum sociis natoque penatibus et magnis dis parturient. Phasellus laoreet lorem vel dolor tempus vehicula. Vivamus sagittis lacus vel augue laoreet rutrum faucibus. Integer legentibus erat a ante historiarum dapibus.
 Quisque ut dolor gravida, placerat libero vel, euismod. Quam temere in vitiis, legem sancimus haerentia. Qui ipsorum lingua Celtae, nostra Galli appellantur. Quis aute iure reprehenderit in voluptate velit esse. Fabio vel iudice vincam, sunt in culpa qui officia. Cras mattis iudicium purus sit amet fermentum.
-Quo usque tandem abutere, Catilina, patientia nostra? Gallia est omnis divisa in partes tres, quarum. Quam diu etiam furor iste tuus nos eludet? Quid securi etiam tamquam eu fugiat nulla pariatur. Curabitur blandit tempus ardua ridiculus sed magna.
+Quo usque tandem abutere, Catilina, patientia nostra? Gallia est omnis divisa in partes tres, quarum. Quam diu etiam furor iste tuus nos eludet? Quid securi etiam tamquam eu fugiat nulla pariatur. Curabitur blandit tempus ardua ridiculous sed magna.
 Magna pars studiorum, prodita quaerimus. Cum ceteris in veneratione tui montes, nascetur mus. Morbi odio eros, volutpat ut pharetra vitae, lobortis sed nibh. Plura mihi bona sunt, inclinet, amari petere vellent. Idque Caesaris facere voluntate liceret: sese habere. Tu quoque, Brute, fili mi, nihil timor populi, nihil!
 Tityre, tu patulae recubans sub tegmine fagi dolor. Inmensae subtilitatis, obscuris et malesuada fames. Quae vero auctorem tractata ab fiducia dicuntur.
 Cum sociis natoque penatibus et magnis dis parturient. Phasellus laoreet lorem vel dolor tempus vehicula. Vivamus sagittis lacus vel augue laoreet rutrum faucibus. Integer legentibus erat a ante historiarum dapibus.
 Quisque ut dolor gravida, placerat libero vel, euismod. Quam temere in vitiis, legem sancimus haerentia. Qui ipsorum lingua Celtae, nostra Galli appellantur. Quis aute iure reprehenderit in voluptate velit esse. Fabio vel iudice vincam, sunt in culpa qui officia. Cras mattis iudicium purus sit amet fermentum.
-Quo usque tandem abutere, Catilina, patientia nostra? Gallia est omnis divisa in partes tres, quarum. Quam diu etiam furor iste tuus nos eludet? Quid securi etiam tamquam eu fugiat nulla pariatur. Curabitur blandit tempus ardua ridiculus sed magna.
+Quo usque tandem abutere, Catilina, patientia nostra? Gallia est omnis divisa in partes tres, quarum. Quam diu etiam furor iste tuus nos eludet? Quid securi etiam tamquam eu fugiat nulla pariatur. Curabitur blandit tempus ardua ridiculous sed magna.
 Magna pars studiorum, prodita quaerimus. Cum ceteris in veneratione tui montes, nascetur mus. Morbi odio eros, volutpat ut pharetra vitae, lobortis sed nibh. Plura mihi bona sunt, inclinet, amari petere vellent. Idque Caesaris facere voluntate liceret: sese habere. Tu quoque, Brute, fili mi, nihil timor populi, nihil!
 Tityre, tu patulae recubans sub tegmine fagi dolor. Inmensae subtilitatis, obscuris et malesuada fames. Quae vero auctorem tractata ab fiducia dicuntur.
 ` + longLine
 	textWithLastNewline = `first line
 Cum sociis natoque penatibus et magnis dis parturient. Phasellus laoreet lorem vel dolor tempus vehicula. Vivamus sagittis lacus vel augue laoreet rutrum faucibus. Integer legentibus erat a ante historiarum dapibus.
 Quisque ut dolor gravida, placerat libero vel, euismod. Quam temere in vitiis, legem sancimus haerentia. Qui ipsorum lingua Celtae, nostra Galli appellantur. Quis aute iure reprehenderit in voluptate velit esse. Fabio vel iudice vincam, sunt in culpa qui officia. Cras mattis iudicium purus sit amet fermentum.
-Quo usque tandem abutere, Catilina, patientia nostra? Gallia est omnis divisa in partes tres, quarum. Quam diu etiam furor iste tuus nos eludet? Quid securi etiam tamquam eu fugiat nulla pariatur. Curabitur blandit tempus ardua ridiculus sed magna.
+Quo usque tandem abutere, Catilina, patientia nostra? Gallia est omnis divisa in partes tres, quarum. Quam diu etiam furor iste tuus nos eludet? Quid securi etiam tamquam eu fugiat nulla pariatur. Curabitur blandit tempus ardua ridiculous sed magna.
 Magna pars studiorum, prodita quaerimus. Cum ceteris in veneratione tui montes, nascetur mus. Morbi odio eros, volutpat ut pharetra vitae, lobortis sed nibh. Plura mihi bona sunt, inclinet, amari petere vellent. Idque Caesaris facere voluntate liceret: sese habere. Tu quoque, Brute, fili mi, nihil timor populi, nihil!
 Tityre, tu patulae recubans sub tegmine fagi dolor. Inmensae subtilitatis, obscuris et malesuada fames. Quae vero auctorem tractata ab fiducia dicuntur.
 Cum sociis natoque penatibus et magnis dis parturient. Phasellus laoreet lorem vel dolor tempus vehicula. Vivamus sagittis lacus vel augue laoreet rutrum faucibus. Integer legentibus erat a ante historiarum dapibus.
 Quisque ut dolor gravida, placerat libero vel, euismod. Quam temere in vitiis, legem sancimus haerentia. Qui ipsorum lingua Celtae, nostra Galli appellantur. Quis aute iure reprehenderit in voluptate velit esse. Fabio vel iudice vincam, sunt in culpa qui officia. Cras mattis iudicium purus sit amet fermentum.
-Quo usque tandem abutere, Catilina, patientia nostra? Gallia est omnis divisa in partes tres, quarum. Quam diu etiam furor iste tuus nos eludet? Quid securi etiam tamquam eu fugiat nulla pariatur. Curabitur blandit tempus ardua ridiculus sed magna.
+Quo usque tandem abutere, Catilina, patientia nostra? Gallia est omnis divisa in partes tres, quarum. Quam diu etiam furor iste tuus nos eludet? Quid securi etiam tamquam eu fugiat nulla pariatur. Curabitur blandit tempus ardua ridiculous sed magna.
 Magna pars studiorum, prodita quaerimus. Cum ceteris in veneratione tui montes, nascetur mus. Morbi odio eros, volutpat ut pharetra vitae, lobortis sed nibh. Plura mihi bona sunt, inclinet, amari petere vellent. Idque Caesaris facere voluntate liceret: sese habere. Tu quoque, Brute, fili mi, nihil timor populi, nihil!
 Tityre, tu patulae recubans sub tegmine fagi dolor. Inmensae subtilitatis, obscuris et malesuada fames. Quae vero auctorem tractata ab fiducia dicuntur.
 Cum sociis natoque penatibus et magnis dis parturient. Phasellus laoreet lorem vel dolor tempus vehicula. Vivamus sagittis lacus vel augue laoreet rutrum faucibus. Integer legentibus erat a ante historiarum dapibus.
 Quisque ut dolor gravida, placerat libero vel, euismod. Quam temere in vitiis, legem sancimus haerentia. Qui ipsorum lingua Celtae, nostra Galli appellantur. Quis aute iure reprehenderit in voluptate velit esse. Fabio vel iudice vincam, sunt in culpa qui officia. Cras mattis iudicium purus sit amet fermentum.
-Quo usque tandem abutere, Catilina, patientia nostra? Gallia est omnis divisa in partes tres, quarum. Quam diu etiam furor iste tuus nos eludet? Quid securi etiam tamquam eu fugiat nulla pariatur. Curabitur blandit tempus ardua ridiculus sed magna.
+Quo usque tandem abutere, Catilina, patientia nostra? Gallia est omnis divisa in partes tres, quarum. Quam diu etiam furor iste tuus nos eludet? Quid securi etiam tamquam eu fugiat nulla pariatur. Curabitur blandit tempus ardua ridiculous sed magna.
 Magna pars studiorum, prodita quaerimus. Cum ceteris in veneratione tui montes, nascetur mus. Morbi odio eros, volutpat ut pharetra vitae, lobortis sed nibh. Plura mihi bona sunt, inclinet, amari petere vellent. Idque Caesaris facere voluntate liceret: sese habere. Tu quoque, Brute, fili mi, nihil timor populi, nihil!
 Tityre, tu patulae recubans sub tegmine fagi dolor. Inmensae subtilitatis, obscuris et malesuada fames. Quae vero auctorem tractata ab fiducia dicuntur.
 ` + longLine + "\n"

core/filex/lookup.go

@@ -5,12 +5,15 @@ import (
 	"os"
 )
 
+// OffsetRange represents a content block of a file.
 type OffsetRange struct {
 	File  string
 	Start int64
 	Stop  int64
 }
 
+// SplitLineChunks splits file into chunks.
+// The whole line are guaranteed to be split in the same chunk.
 func SplitLineChunks(filename string, chunks int) ([]OffsetRange, error) {
 	info, err := os.Stat(filename)
 	if err != nil {

core/filex/progressscanner.go

@@ -3,8 +3,11 @@ package filex
 import "gopkg.in/cheggaaa/pb.v1"
 
 type (
+	// A Scanner is used to read lines.
 	Scanner interface {
+		// Scan checks if has remaining to read.
 		Scan() bool
+		// Text returns next line.
 		Text() string
 	}
 
@@ -14,6 +17,7 @@ type (
 	}
 )
 
+// NewProgressScanner returns a Scanner with progress indicator.
 func NewProgressScanner(scanner Scanner, bar *pb.ProgressBar) Scanner {
 	return &progressScanner{
 		Scanner: scanner,

core/filex/rangereader.go

@@ -5,12 +5,14 @@ import (
 	"os"
 )
 
+// A RangeReader is used to read a range of content from a file.
 type RangeReader struct {
 	file  *os.File
 	start int64
 	stop  int64
 }
 
+// NewRangeReader returns a RangeReader, which will read the range of content from file.
 func NewRangeReader(file *os.File, start, stop int64) *RangeReader {
 	return &RangeReader{
 		file:  file,
@@ -19,6 +21,7 @@ func NewRangeReader(file *os.File, start, stop int64) *RangeReader {
 	}
 }
 
+// Read reads the range of content into p.
 func (rr *RangeReader) Read(p []byte) (n int, err error) {
 	stat, err := rr.file.Stat()
 	if err != nil {

core/fs/files+polyfill.go

@@ -1,3 +1,4 @@
+//go:build windows
 // +build windows
 
 package fs

core/fs/files.go

@@ -7,6 +7,7 @@ import (
 	"syscall"
 )
 
+// CloseOnExec makes sure closing the file on process forking.
 func CloseOnExec(file *os.File) {
 	if file != nil {
 		syscall.CloseOnExec(int(file.Fd()))

core/fx/fn.go

@@ -1,357 +0,0 @@
-package fx
-
-import (
-	"sort"
-	"sync"
-
-	"github.com/tal-tech/go-zero/core/collection"
-	"github.com/tal-tech/go-zero/core/lang"
-	"github.com/tal-tech/go-zero/core/threading"
-)
-
-const (
-	defaultWorkers = 16
-	minWorkers     = 1
-)
-
-type (
-	rxOptions struct {
-		unlimitedWorkers bool
-		workers          int
-	}
-
-	FilterFunc   func(item interface{}) bool
-	ForAllFunc   func(pipe <-chan interface{})
-	ForEachFunc  func(item interface{})
-	GenerateFunc func(source chan<- interface{})
-	KeyFunc      func(item interface{}) interface{}
-	LessFunc     func(a, b interface{}) bool
-	MapFunc      func(item interface{}) interface{}
-	Option       func(opts *rxOptions)
-	ParallelFunc func(item interface{})
-	ReduceFunc   func(pipe <-chan interface{}) (interface{}, error)
-	WalkFunc     func(item interface{}, pipe chan<- interface{})
-
-	Stream struct {
-		source <-chan interface{}
-	}
-)
-
-// From constructs a Stream from the given GenerateFunc.
-func From(generate GenerateFunc) Stream {
-	source := make(chan interface{})
-
-	threading.GoSafe(func() {
-		defer close(source)
-		generate(source)
-	})
-
-	return Range(source)
-}
-
-// Just converts the given arbitary items to a Stream.
-func Just(items ...interface{}) Stream {
-	source := make(chan interface{}, len(items))
-	for _, item := range items {
-		source <- item
-	}
-	close(source)
-
-	return Range(source)
-}
-
-// Range converts the given channel to a Stream.
-func Range(source <-chan interface{}) Stream {
-	return Stream{
-		source: source,
-	}
-}
-
-// Buffer buffers the items into a queue with size n.
-func (p Stream) Buffer(n int) Stream {
-	if n < 0 {
-		n = 0
-	}
-
-	source := make(chan interface{}, n)
-	go func() {
-		for item := range p.source {
-			source <- item
-		}
-		close(source)
-	}()
-
-	return Range(source)
-}
-
-// Distinct removes the duplicated items base on the given KeyFunc.
-func (p Stream) Distinct(fn KeyFunc) Stream {
-	source := make(chan interface{})
-
-	threading.GoSafe(func() {
-		defer close(source)
-
-		keys := make(map[interface{}]lang.PlaceholderType)
-		for item := range p.source {
-			key := fn(item)
-			if _, ok := keys[key]; !ok {
-				source <- item
-				keys[key] = lang.Placeholder
-			}
-		}
-	})
-
-	return Range(source)
-}
-
-// Done waits all upstreaming operations to be done.
-func (p Stream) Done() {
-	for range p.source {
-	}
-}
-
-// Filter filters the items by the given FilterFunc.
-func (p Stream) Filter(fn FilterFunc, opts ...Option) Stream {
-	return p.Walk(func(item interface{}, pipe chan<- interface{}) {
-		if fn(item) {
-			pipe <- item
-		}
-	}, opts...)
-}
-
-// ForAll handles the streaming elements from the source and no later streams.
-func (p Stream) ForAll(fn ForAllFunc) {
-	fn(p.source)
-}
-
-// ForEach seals the Stream with the ForEachFunc on each item, no successive operations.
-func (p Stream) ForEach(fn ForEachFunc) {
-	for item := range p.source {
-		fn(item)
-	}
-}
-
-// Group groups the elements into different groups based on their keys.
-func (p Stream) Group(fn KeyFunc) Stream {
-	groups := make(map[interface{}][]interface{})
-	for item := range p.source {
-		key := fn(item)
-		groups[key] = append(groups[key], item)
-	}
-
-	source := make(chan interface{})
-	go func() {
-		for _, group := range groups {
-			source <- group
-		}
-		close(source)
-	}()
-
-	return Range(source)
-}
-
-func (p Stream) Head(n int64) Stream {
-	source := make(chan interface{})
-
-	go func() {
-		for item := range p.source {
-			n--
-			if n >= 0 {
-				source <- item
-			}
-			if n == 0 {
-				// let successive method go ASAP even we have more items to skip
-				// why we don't just break the loop, because if break,
-				// this former goroutine will block forever, which will cause goroutine leak.
-				close(source)
-			}
-		}
-		if n > 0 {
-			close(source)
-		}
-	}()
-
-	return Range(source)
-}
-
-// Maps converts each item to another corresponding item, which means it's a 1:1 model.
-func (p Stream) Map(fn MapFunc, opts ...Option) Stream {
-	return p.Walk(func(item interface{}, pipe chan<- interface{}) {
-		pipe <- fn(item)
-	}, opts...)
-}
-
-// Merge merges all the items into a slice and generates a new stream.
-func (p Stream) Merge() Stream {
-	var items []interface{}
-	for item := range p.source {
-		items = append(items, item)
-	}
-
-	source := make(chan interface{}, 1)
-	source <- items
-	close(source)
-
-	return Range(source)
-}
-
-// Parallel applies the given ParallenFunc to each item concurrently with given number of workers.
-func (p Stream) Parallel(fn ParallelFunc, opts ...Option) {
-	p.Walk(func(item interface{}, pipe chan<- interface{}) {
-		fn(item)
-	}, opts...).Done()
-}
-
-// Reduce is a utility method to let the caller deal with the underlying channel.
-func (p Stream) Reduce(fn ReduceFunc) (interface{}, error) {
-	return fn(p.source)
-}
-
-// Reverse reverses the elements in the stream.
-func (p Stream) Reverse() Stream {
-	var items []interface{}
-	for item := range p.source {
-		items = append(items, item)
-	}
-	// reverse, official method
-	for i := len(items)/2 - 1; i >= 0; i-- {
-		opp := len(items) - 1 - i
-		items[i], items[opp] = items[opp], items[i]
-	}
-
-	return Just(items...)
-}
-
-// Sort sorts the items from the underlying source.
-func (p Stream) Sort(less LessFunc) Stream {
-	var items []interface{}
-	for item := range p.source {
-		items = append(items, item)
-	}
-	sort.Slice(items, func(i, j int) bool {
-		return less(items[i], items[j])
-	})
-
-	return Just(items...)
-}
-
-func (p Stream) Tail(n int64) Stream {
-	source := make(chan interface{})
-
-	go func() {
-		ring := collection.NewRing(int(n))
-		for item := range p.source {
-			ring.Add(item)
-		}
-		for _, item := range ring.Take() {
-			source <- item
-		}
-		close(source)
-	}()
-
-	return Range(source)
-}
-
-// Walk lets the callers handle each item, the caller may write zero, one or more items base on the given item.
-func (p Stream) Walk(fn WalkFunc, opts ...Option) Stream {
-	option := buildOptions(opts...)
-	if option.unlimitedWorkers {
-		return p.walkUnlimited(fn, option)
-	} else {
-		return p.walkLimited(fn, option)
-	}
-}
-
-func (p Stream) walkLimited(fn WalkFunc, option *rxOptions) Stream {
-	pipe := make(chan interface{}, option.workers)
-
-	go func() {
-		var wg sync.WaitGroup
-		pool := make(chan lang.PlaceholderType, option.workers)
-
-		for {
-			pool <- lang.Placeholder
-			item, ok := <-p.source
-			if !ok {
-				<-pool
-				break
-			}
-
-			wg.Add(1)
-			// better to safely run caller defined method
-			threading.GoSafe(func() {
-				defer func() {
-					wg.Done()
-					<-pool
-				}()
-
-				fn(item, pipe)
-			})
-		}
-
-		wg.Wait()
-		close(pipe)
-	}()
-
-	return Range(pipe)
-}
-
-func (p Stream) walkUnlimited(fn WalkFunc, option *rxOptions) Stream {
-	pipe := make(chan interface{}, defaultWorkers)
-
-	go func() {
-		var wg sync.WaitGroup
-
-		for {
-			item, ok := <-p.source
-			if !ok {
-				break
-			}
-
-			wg.Add(1)
-			// better to safely run caller defined method
-			threading.GoSafe(func() {
-				defer wg.Done()
-				fn(item, pipe)
-			})
-		}
-
-		wg.Wait()
-		close(pipe)
-	}()
-
-	return Range(pipe)
-}
-
-// UnlimitedWorkers lets the caller to use as many workers as the tasks.
-func UnlimitedWorkers() Option {
-	return func(opts *rxOptions) {
-		opts.unlimitedWorkers = true
-	}
-}
-
-// WithWorkers lets the caller to customize the concurrent workers.
-func WithWorkers(workers int) Option {
-	return func(opts *rxOptions) {
-		if workers < minWorkers {
-			opts.workers = minWorkers
-		} else {
-			opts.workers = workers
-		}
-	}
-}
-
-func buildOptions(opts ...Option) *rxOptions {
-	options := newOptions()
-	for _, opt := range opts {
-		opt(options)
-	}
-
-	return options
-}
-
-func newOptions() *rxOptions {
-	return &rxOptions{
-		workers: defaultWorkers,
-	}
-}

core/fx/parallel.go

@@ -2,6 +2,7 @@ package fx
 
 import "github.com/tal-tech/go-zero/core/threading"
 
+// Parallel runs fns parallelly and waits for done.
 func Parallel(fns ...func()) {
 	group := threading.NewRoutineGroup()
 	for _, fn := range fns {

core/fx/retry.go

@@ -5,6 +5,7 @@ import "github.com/tal-tech/go-zero/core/errorx"
 const defaultRetryTimes = 3
 
 type (
+	// RetryOption defines the method to customize DoWithRetry.
 	RetryOption func(*retryOptions)
 
 	retryOptions struct {
@@ -12,8 +13,9 @@ type (
 	}
 )
 
-func DoWithRetries(fn func() error, opts ...RetryOption) error {
-	var options = newRetryOptions()
+// DoWithRetry runs fn, and retries if failed. Default to retry 3 times.
+func DoWithRetry(fn func() error, opts ...RetryOption) error {
+	options := newRetryOptions()
 	for _, opt := range opts {
 		opt(options)
 	}
@@ -30,7 +32,8 @@ func DoWithRetries(fn func() error, opts ...RetryOption) error {
 	return berr.Err()
 }
 
-func WithRetries(times int) RetryOption {
+// WithRetry customize a DoWithRetry call with given retry times.
+func WithRetry(times int) RetryOption {
 	return func(options *retryOptions) {
 		options.times = times
 	}

core/fx/retry_test.go

@@ -8,12 +8,12 @@ import (
 )
 
 func TestRetry(t *testing.T) {
-	assert.NotNil(t, DoWithRetries(func() error {
+	assert.NotNil(t, DoWithRetry(func() error {
 		return errors.New("any")
 	}))
 
 	var times int
-	assert.Nil(t, DoWithRetries(func() error {
+	assert.Nil(t, DoWithRetry(func() error {
 		times++
 		if times == defaultRetryTimes {
 			return nil
@@ -22,7 +22,7 @@ func TestRetry(t *testing.T) {
 	}))
 
 	times = 0
-	assert.NotNil(t, DoWithRetries(func() error {
+	assert.NotNil(t, DoWithRetry(func() error {
 		times++
 		if times == defaultRetryTimes+1 {
 			return nil
@@ -30,13 +30,13 @@ func TestRetry(t *testing.T) {
 		return errors.New("any")
 	}))
 
-	var total = 2 * defaultRetryTimes
+	total := 2 * defaultRetryTimes
 	times = 0
-	assert.Nil(t, DoWithRetries(func() error {
+	assert.Nil(t, DoWithRetry(func() error {
 		times++
 		if times == total {
 			return nil
 		}
 		return errors.New("any")
-	}, WithRetries(total)))
+	}, WithRetry(total)))
 }

core/fx/stream.go

@@ -0,0 +1,499 @@
+package fx
+
+import (
+	"sort"
+	"sync"
+
+	"github.com/tal-tech/go-zero/core/collection"
+	"github.com/tal-tech/go-zero/core/lang"
+	"github.com/tal-tech/go-zero/core/threading"
+)
+
+const (
+	defaultWorkers = 16
+	minWorkers     = 1
+)
+
+type (
+	rxOptions struct {
+		unlimitedWorkers bool
+		workers          int
+	}
+
+	// FilterFunc defines the method to filter a Stream.
+	FilterFunc func(item interface{}) bool
+	// ForAllFunc defines the method to handle all elements in a Stream.
+	ForAllFunc func(pipe <-chan interface{})
+	// ForEachFunc defines the method to handle each element in a Stream.
+	ForEachFunc func(item interface{})
+	// GenerateFunc defines the method to send elements into a Stream.
+	GenerateFunc func(source chan<- interface{})
+	// KeyFunc defines the method to generate keys for the elements in a Stream.
+	KeyFunc func(item interface{}) interface{}
+	// LessFunc defines the method to compare the elements in a Stream.
+	LessFunc func(a, b interface{}) bool
+	// MapFunc defines the method to map each element to another object in a Stream.
+	MapFunc func(item interface{}) interface{}
+	// Option defines the method to customize a Stream.
+	Option func(opts *rxOptions)
+	// ParallelFunc defines the method to handle elements parallelly.
+	ParallelFunc func(item interface{})
+	// ReduceFunc defines the method to reduce all the elements in a Stream.
+	ReduceFunc func(pipe <-chan interface{}) (interface{}, error)
+	// WalkFunc defines the method to walk through all the elements in a Stream.
+	WalkFunc func(item interface{}, pipe chan<- interface{})
+
+	// A Stream is a stream that can be used to do stream processing.
+	Stream struct {
+		source <-chan interface{}
+	}
+)
+
+// Concat returns a concatenated Stream.
+func Concat(s Stream, others ...Stream) Stream {
+	return s.Concat(others...)
+}
+
+// From constructs a Stream from the given GenerateFunc.
+func From(generate GenerateFunc) Stream {
+	source := make(chan interface{})
+
+	threading.GoSafe(func() {
+		defer close(source)
+		generate(source)
+	})
+
+	return Range(source)
+}
+
+// Just converts the given arbitrary items to a Stream.
+func Just(items ...interface{}) Stream {
+	source := make(chan interface{}, len(items))
+	for _, item := range items {
+		source <- item
+	}
+	close(source)
+
+	return Range(source)
+}
+
+// Range converts the given channel to a Stream.
+func Range(source <-chan interface{}) Stream {
+	return Stream{
+		source: source,
+	}
+}
+
+// AllMach returns whether all elements of this stream match the provided predicate.
+// May not evaluate the predicate on all elements if not necessary for determining the result.
+// If the stream is empty then true is returned and the predicate is not evaluated.
+func (s Stream) AllMach(predicate func(item interface{}) bool) bool {
+	for item := range s.source {
+		if !predicate(item) {
+			return false
+		}
+	}
+
+	return true
+}
+
+// AnyMach returns whether any elements of this stream match the provided predicate.
+// May not evaluate the predicate on all elements if not necessary for determining the result.
+// If the stream is empty then false is returned and the predicate is not evaluated.
+func (s Stream) AnyMach(predicate func(item interface{}) bool) bool {
+	for item := range s.source {
+		if predicate(item) {
+			return true
+		}
+	}
+
+	return false
+}
+
+// Buffer buffers the items into a queue with size n.
+// It can balance the producer and the consumer if their processing throughput don't match.
+func (s Stream) Buffer(n int) Stream {
+	if n < 0 {
+		n = 0
+	}
+
+	source := make(chan interface{}, n)
+	go func() {
+		for item := range s.source {
+			source <- item
+		}
+		close(source)
+	}()
+
+	return Range(source)
+}
+
+// Concat returns a Stream that concatenated other streams
+func (s Stream) Concat(others ...Stream) Stream {
+	source := make(chan interface{})
+
+	go func() {
+		group := threading.NewRoutineGroup()
+		group.Run(func() {
+			for item := range s.source {
+				source <- item
+			}
+		})
+
+		for _, each := range others {
+			each := each
+			group.Run(func() {
+				for item := range each.source {
+					source <- item
+				}
+			})
+		}
+
+		group.Wait()
+		close(source)
+	}()
+
+	return Range(source)
+}
+
+// Count counts the number of elements in the result.
+func (s Stream) Count() (count int) {
+	for range s.source {
+		count++
+	}
+	return
+}
+
+// Distinct removes the duplicated items base on the given KeyFunc.
+func (s Stream) Distinct(fn KeyFunc) Stream {
+	source := make(chan interface{})
+
+	threading.GoSafe(func() {
+		defer close(source)
+
+		keys := make(map[interface{}]lang.PlaceholderType)
+		for item := range s.source {
+			key := fn(item)
+			if _, ok := keys[key]; !ok {
+				source <- item
+				keys[key] = lang.Placeholder
+			}
+		}
+	})
+
+	return Range(source)
+}
+
+// Done waits all upstreaming operations to be done.
+func (s Stream) Done() {
+	for range s.source {
+	}
+}
+
+// Filter filters the items by the given FilterFunc.
+func (s Stream) Filter(fn FilterFunc, opts ...Option) Stream {
+	return s.Walk(func(item interface{}, pipe chan<- interface{}) {
+		if fn(item) {
+			pipe <- item
+		}
+	}, opts...)
+}
+
+// ForAll handles the streaming elements from the source and no later streams.
+func (s Stream) ForAll(fn ForAllFunc) {
+	fn(s.source)
+}
+
+// ForEach seals the Stream with the ForEachFunc on each item, no successive operations.
+func (s Stream) ForEach(fn ForEachFunc) {
+	for item := range s.source {
+		fn(item)
+	}
+}
+
+// Group groups the elements into different groups based on their keys.
+func (s Stream) Group(fn KeyFunc) Stream {
+	groups := make(map[interface{}][]interface{})
+	for item := range s.source {
+		key := fn(item)
+		groups[key] = append(groups[key], item)
+	}
+
+	source := make(chan interface{})
+	go func() {
+		for _, group := range groups {
+			source <- group
+		}
+		close(source)
+	}()
+
+	return Range(source)
+}
+
+// Head returns the first n elements in p.
+func (s Stream) Head(n int64) Stream {
+	if n < 1 {
+		panic("n must be greater than 0")
+	}
+
+	source := make(chan interface{})
+
+	go func() {
+		for item := range s.source {
+			n--
+			if n >= 0 {
+				source <- item
+			}
+			if n == 0 {
+				// let successive method go ASAP even we have more items to skip
+				// why we don't just break the loop, because if break,
+				// this former goroutine will block forever, which will cause goroutine leak.
+				close(source)
+			}
+		}
+		if n > 0 {
+			close(source)
+		}
+	}()
+
+	return Range(source)
+}
+
+// Map converts each item to another corresponding item, which means it's a 1:1 model.
+func (s Stream) Map(fn MapFunc, opts ...Option) Stream {
+	return s.Walk(func(item interface{}, pipe chan<- interface{}) {
+		pipe <- fn(item)
+	}, opts...)
+}
+
+// Merge merges all the items into a slice and generates a new stream.
+func (s Stream) Merge() Stream {
+	var items []interface{}
+	for item := range s.source {
+		items = append(items, item)
+	}
+
+	source := make(chan interface{}, 1)
+	source <- items
+	close(source)
+
+	return Range(source)
+}
+
+// Parallel applies the given ParallelFunc to each item concurrently with given number of workers.
+func (s Stream) Parallel(fn ParallelFunc, opts ...Option) {
+	s.Walk(func(item interface{}, pipe chan<- interface{}) {
+		fn(item)
+	}, opts...).Done()
+}
+
+// Reduce is a utility method to let the caller deal with the underlying channel.
+func (s Stream) Reduce(fn ReduceFunc) (interface{}, error) {
+	return fn(s.source)
+}
+
+// Reverse reverses the elements in the stream.
+func (s Stream) Reverse() Stream {
+	var items []interface{}
+	for item := range s.source {
+		items = append(items, item)
+	}
+	// reverse, official method
+	for i := len(items)/2 - 1; i >= 0; i-- {
+		opp := len(items) - 1 - i
+		items[i], items[opp] = items[opp], items[i]
+	}
+
+	return Just(items...)
+}
+
+// Skip returns a Stream that skips size elements.
+func (s Stream) Skip(n int64) Stream {
+	if n < 0 {
+		panic("n must not be negative")
+	}
+	if n == 0 {
+		return s
+	}
+
+	source := make(chan interface{})
+
+	go func() {
+		for item := range s.source {
+			n--
+			if n >= 0 {
+				continue
+			} else {
+				source <- item
+			}
+		}
+		close(source)
+	}()
+
+	return Range(source)
+}
+
+// Sort sorts the items from the underlying source.
+func (s Stream) Sort(less LessFunc) Stream {
+	var items []interface{}
+	for item := range s.source {
+		items = append(items, item)
+	}
+	sort.Slice(items, func(i, j int) bool {
+		return less(items[i], items[j])
+	})
+
+	return Just(items...)
+}
+
+// Split splits the elements into chunk with size up to n,
+// might be less than n on tailing elements.
+func (s Stream) Split(n int) Stream {
+	if n < 1 {
+		panic("n should be greater than 0")
+	}
+
+	source := make(chan interface{})
+	go func() {
+		var chunk []interface{}
+		for item := range s.source {
+			chunk = append(chunk, item)
+			if len(chunk) == n {
+				source <- chunk
+				chunk = nil
+			}
+		}
+		if chunk != nil {
+			source <- chunk
+		}
+		close(source)
+	}()
+
+	return Range(source)
+}
+
+// Tail returns the last n elements in p.
+func (s Stream) Tail(n int64) Stream {
+	if n < 1 {
+		panic("n should be greater than 0")
+	}
+
+	source := make(chan interface{})
+
+	go func() {
+		ring := collection.NewRing(int(n))
+		for item := range s.source {
+			ring.Add(item)
+		}
+		for _, item := range ring.Take() {
+			source <- item
+		}
+		close(source)
+	}()
+
+	return Range(source)
+}
+
+// Walk lets the callers handle each item, the caller may write zero, one or more items base on the given item.
+func (s Stream) Walk(fn WalkFunc, opts ...Option) Stream {
+	option := buildOptions(opts...)
+	if option.unlimitedWorkers {
+		return s.walkUnlimited(fn, option)
+	}
+
+	return s.walkLimited(fn, option)
+}
+
+func (s Stream) walkLimited(fn WalkFunc, option *rxOptions) Stream {
+	pipe := make(chan interface{}, option.workers)
+
+	go func() {
+		var wg sync.WaitGroup
+		pool := make(chan lang.PlaceholderType, option.workers)
+
+		for {
+			pool <- lang.Placeholder
+			item, ok := <-s.source
+			if !ok {
+				<-pool
+				break
+			}
+
+			wg.Add(1)
+			// better to safely run caller defined method
+			threading.GoSafe(func() {
+				defer func() {
+					wg.Done()
+					<-pool
+				}()
+
+				fn(item, pipe)
+			})
+		}
+
+		wg.Wait()
+		close(pipe)
+	}()
+
+	return Range(pipe)
+}
+
+func (s Stream) walkUnlimited(fn WalkFunc, option *rxOptions) Stream {
+	pipe := make(chan interface{}, defaultWorkers)
+
+	go func() {
+		var wg sync.WaitGroup
+
+		for {
+			item, ok := <-s.source
+			if !ok {
+				break
+			}
+
+			wg.Add(1)
+			// better to safely run caller defined method
+			threading.GoSafe(func() {
+				defer wg.Done()
+				fn(item, pipe)
+			})
+		}
+
+		wg.Wait()
+		close(pipe)
+	}()
+
+	return Range(pipe)
+}
+
+// UnlimitedWorkers lets the caller to use as many workers as the tasks.
+func UnlimitedWorkers() Option {
+	return func(opts *rxOptions) {
+		opts.unlimitedWorkers = true
+	}
+}
+
+// WithWorkers lets the caller to customize the concurrent workers.
+func WithWorkers(workers int) Option {
+	return func(opts *rxOptions) {
+		if workers < minWorkers {
+			opts.workers = minWorkers
+		} else {
+			opts.workers = workers
+		}
+	}
+}
+
+func buildOptions(opts ...Option) *rxOptions {
+	options := newOptions()
+	for _, opt := range opts {
+		opt(options)
+	}
+
+	return options
+}
+
+func newOptions() *rxOptions {
+	return &rxOptions{
+		workers: defaultWorkers,
+	}
+}

core/fx/stream_test.go

@@ -3,7 +3,10 @@ package fx
 import (
 	"io/ioutil"
 	"log"
+	"math/rand"
+	"reflect"
 	"runtime"
+	"sort"
 	"sync"
 	"sync/atomic"
 	"testing"
@@ -49,6 +52,36 @@ func TestBufferNegative(t *testing.T) {
 	assert.Equal(t, 10, result)
 }
 
+func TestCount(t *testing.T) {
+	tests := []struct {
+		name     string
+		elements []interface{}
+	}{
+		{
+			name: "no elements with nil",
+		},
+		{
+			name:     "no elements",
+			elements: []interface{}{},
+		},
+		{
+			name:     "1 element",
+			elements: []interface{}{1},
+		},
+		{
+			name:     "multiple elements",
+			elements: []interface{}{1, 2, 3},
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			val := Just(test.elements...).Count()
+			assert.Equal(t, len(test.elements), val)
+		})
+	}
+}
+
 func TestDone(t *testing.T) {
 	var count int32
 	Just(1, 2, 3).Walk(func(item interface{}, pipe chan<- interface{}) {
@@ -139,6 +172,14 @@ func TestHead(t *testing.T) {
 	assert.Equal(t, 3, result)
 }
 
+func TestHeadZero(t *testing.T) {
+	assert.Panics(t, func() {
+		Just(1, 2, 3, 4).Head(0).Reduce(func(pipe <-chan interface{}) (interface{}, error) {
+			return nil, nil
+		})
+	})
+}
+
 func TestHeadMore(t *testing.T) {
 	var result int
 	Just(1, 2, 3, 4).Head(6).Reduce(func(pipe <-chan interface{}) (interface{}, error) {
@@ -245,6 +286,22 @@ func TestSort(t *testing.T) {
 	})
 }
 
+func TestSplit(t *testing.T) {
+	assert.Panics(t, func() {
+		Just(1, 2, 3, 4, 5, 6, 7, 8, 9, 10).Split(0).Done()
+	})
+	var chunks [][]interface{}
+	Just(1, 2, 3, 4, 5, 6, 7, 8, 9, 10).Split(4).ForEach(func(item interface{}) {
+		chunk := item.([]interface{})
+		chunks = append(chunks, chunk)
+	})
+	assert.EqualValues(t, [][]interface{}{
+		{1, 2, 3, 4},
+		{5, 6, 7, 8},
+		{9, 10},
+	}, chunks)
+}
+
 func TestTail(t *testing.T) {
 	var result int
 	Just(1, 2, 3, 4).Tail(2).Reduce(func(pipe <-chan interface{}) (interface{}, error) {
@@ -256,6 +313,14 @@ func TestTail(t *testing.T) {
 	assert.Equal(t, 7, result)
 }
 
+func TestTailZero(t *testing.T) {
+	assert.Panics(t, func() {
+		Just(1, 2, 3, 4).Tail(0).Reduce(func(pipe <-chan interface{}) (interface{}, error) {
+			return nil, nil
+		})
+	})
+}
+
 func TestWalk(t *testing.T) {
 	var result int
 	Just(1, 2, 3, 4, 5).Walk(func(item interface{}, pipe chan<- interface{}) {
@@ -268,6 +333,29 @@ func TestWalk(t *testing.T) {
 	assert.Equal(t, 9, result)
 }
 
+func BenchmarkParallelMapReduce(b *testing.B) {
+	b.ReportAllocs()
+
+	mapper := func(v interface{}) interface{} {
+		return v.(int64) * v.(int64)
+	}
+	reducer := func(input <-chan interface{}) (interface{}, error) {
+		var result int64
+		for v := range input {
+			result += v.(int64)
+		}
+		return result, nil
+	}
+	b.ResetTimer()
+	From(func(input chan<- interface{}) {
+		b.RunParallel(func(pb *testing.PB) {
+			for pb.Next() {
+				input <- int64(rand.Int())
+			}
+		})
+	}).Map(mapper).Reduce(reducer)
+}
+
 func BenchmarkMapReduce(b *testing.B) {
 	b.ReportAllocs()
 
@@ -281,12 +369,103 @@ func BenchmarkMapReduce(b *testing.B) {
 		}
 		return result, nil
 	}
+	b.ResetTimer()
+	From(func(input chan<- interface{}) {
+		for i := 0; i < b.N; i++ {
+			input <- int64(rand.Int())
+		}
+	}).Map(mapper).Reduce(reducer)
+}
 
-	for i := 0; i < b.N; i++ {
-		From(func(input chan<- interface{}) {
-			for j := 0; j < 2; j++ {
-				input <- int64(j)
-			}
-		}).Map(mapper).Reduce(reducer)
+func equal(t *testing.T, stream Stream, data []interface{}) {
+	items := make([]interface{}, 0)
+	for item := range stream.source {
+		items = append(items, item)
+	}
+	if !reflect.DeepEqual(items, data) {
+		t.Errorf(" %v, want %v", items, data)
 	}
 }
+
+func assetEqual(t *testing.T, except, data interface{}) {
+	if !reflect.DeepEqual(except, data) {
+		t.Errorf(" %v, want %v", data, except)
+	}
+}
+
+func TestStream_AnyMach(t *testing.T) {
+	assetEqual(t, false, Just(1, 2, 3).AnyMach(func(item interface{}) bool {
+		return 4 == item.(int)
+	}))
+	assetEqual(t, false, Just(1, 2, 3).AnyMach(func(item interface{}) bool {
+		return 0 == item.(int)
+	}))
+	assetEqual(t, true, Just(1, 2, 3).AnyMach(func(item interface{}) bool {
+		return 2 == item.(int)
+	}))
+	assetEqual(t, true, Just(1, 2, 3).AnyMach(func(item interface{}) bool {
+		return 2 == item.(int)
+	}))
+}
+
+func TestStream_AllMach(t *testing.T) {
+	assetEqual(
+		t, true, Just(1, 2, 3).AllMach(func(item interface{}) bool {
+			return true
+		}),
+	)
+	assetEqual(
+		t, false, Just(1, 2, 3).AllMach(func(item interface{}) bool {
+			return false
+		}),
+	)
+	assetEqual(
+		t, false, Just(1, 2, 3).AllMach(func(item interface{}) bool {
+			return item.(int) == 1
+		}),
+	)
+}
+
+func TestConcat(t *testing.T) {
+	a1 := []interface{}{1, 2, 3}
+	a2 := []interface{}{4, 5, 6}
+	s1 := Just(a1...)
+	s2 := Just(a2...)
+	stream := Concat(s1, s2)
+	var items []interface{}
+	for item := range stream.source {
+		items = append(items, item)
+	}
+	sort.Slice(items, func(i, j int) bool {
+		return items[i].(int) < items[j].(int)
+	})
+	ints := make([]interface{}, 0)
+	ints = append(ints, a1...)
+	ints = append(ints, a2...)
+	assetEqual(t, ints, items)
+}
+
+func TestStream_Skip(t *testing.T) {
+	assetEqual(t, 3, Just(1, 2, 3, 4).Skip(1).Count())
+	assetEqual(t, 1, Just(1, 2, 3, 4).Skip(3).Count())
+	assetEqual(t, 4, Just(1, 2, 3, 4).Skip(0).Count())
+	equal(t, Just(1, 2, 3, 4).Skip(3), []interface{}{4})
+	assert.Panics(t, func() {
+		Just(1, 2, 3, 4).Skip(-1)
+	})
+}
+
+func TestStream_Concat(t *testing.T) {
+	stream := Just(1).Concat(Just(2), Just(3))
+	var items []interface{}
+	for item := range stream.source {
+		items = append(items, item)
+	}
+	sort.Slice(items, func(i, j int) bool {
+		return items[i].(int) < items[j].(int)
+	})
+	assetEqual(t, []interface{}{1, 2, 3}, items)
+
+	just := Just(1)
+	equal(t, just.Concat(just), []interface{}{1})
+}

core/fx/timeout.go

@@ -2,17 +2,24 @@ package fx
 
 import (
 	"context"
+	"fmt"
+	"runtime/debug"
+	"strings"
 	"time"
 )
 
 var (
+	// ErrCanceled is the error returned when the context is canceled.
 	ErrCanceled = context.Canceled
-	ErrTimeout  = context.DeadlineExceeded
+	// ErrTimeout is the error returned when the context's deadline passes.
+	ErrTimeout = context.DeadlineExceeded
 )
 
-type FxOption func() context.Context
+// DoOption defines the method to customize a DoWithTimeout call.
+type DoOption func() context.Context
 
-func DoWithTimeout(fn func() error, timeout time.Duration, opts ...FxOption) error {
+// DoWithTimeout runs fn with timeout control.
+func DoWithTimeout(fn func() error, timeout time.Duration, opts ...DoOption) error {
 	parentCtx := context.Background()
 	for _, opt := range opts {
 		parentCtx = opt()
@@ -20,16 +27,17 @@ func DoWithTimeout(fn func() error, timeout time.Duration, opts ...FxOption) err
 	ctx, cancel := context.WithTimeout(parentCtx, timeout)
 	defer cancel()
 
-	done := make(chan error)
+	// create channel with buffer size 1 to avoid goroutine leak
+	done := make(chan error, 1)
 	panicChan := make(chan interface{}, 1)
 	go func() {
 		defer func() {
 			if p := recover(); p != nil {
-				panicChan <- p
+				// attach call stack to avoid missing in different goroutine
+				panicChan <- fmt.Sprintf("%+v\n\n%s", p, strings.TrimSpace(string(debug.Stack())))
 			}
 		}()
 		done <- fn()
-		close(done)
 	}()
 
 	select {
@@ -42,7 +50,8 @@ func DoWithTimeout(fn func() error, timeout time.Duration, opts ...FxOption) err
 	}
 }
 
-func WithContext(ctx context.Context) FxOption {
+// WithContext customizes a DoWithTimeout call with given ctx.
+func WithContext(ctx context.Context) DoOption {
 	return func() context.Context {
 		return ctx
 	}